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Dothan Review: Powerful and low-power

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July 21, 2004 6:05:57 PM

Anandtech has just <A HREF="http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=212..." target="_new">posted</A> this very interesting review of the new Pentium M. It's really very sad to see this architecture being passed away as a possible desktop dual-core solution; if it were given all the bells and whistles (current P4 FSB, dual-channel memory controller, x86-64 technology) it would be a worthy contender even to the 2Ghz A64!

Why try to put two prescotts on one die, if you can put two 2Ghz Dothans on a die (they're even slightly smaller) and end up with a 4MB cache, 2x2Ghz cpu with <b>42W</b> of heat dissipation? One dual-core dothan would consume far less than a single-core A64 or P4, easily.

Why don't you call in your arbiter chip in dothan and release <b>it</b> instead of a dual-core prescott, Intel?.... :eek: 

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 21, 2004 6:14:39 PM

I fully understand your point! I personnaly think that Dothan have the potential to be the Athlon 64 "killer". But, Intel must make money with the Prescott, they need ROI on this technology and most home users don't care about heat issue and power requirements.

Dothan was designed with mobility in mind and Intel succeeded with this design and it's so bad for users like us who would consider this chip for desktop use if they were available.

--
Asus A7N8X / <font color=green><b>AMD Sempron 2800+</b></font color=green> (tbred @ 167x12)
Kingston DDR333 2x256Megs
<font color=red>Built by ATI Radeon 8500LE 128Megs</font color=red> @ C:275/M:290
July 21, 2004 6:23:34 PM

yeh it is a good idea for a dual core dothan. but intel are being themselfs. (being stupid)
Related resources
July 21, 2004 7:27:41 PM

once again, dont forget that amd could easily release dual core opterons with a total of 66W if using the current low voltage 33W model and thats on 130nm. if they can pull of 90nm without a hitch, you could see it at the same low voltage as dothan. as far as performance, they are oh so clsoe in many areas, but the problem for intel is, if they switch over to dothan, they will sacrifice the elads they have in a few areas over the athlon 64 in the short term. for instance in video editing and rendering, which have been intel strongholds. i dont think they want to ever hear anyoen say athlon is better across the board performance wise, no matter what the cost lol.
July 21, 2004 7:56:23 PM

"If" can sometimes be a rather pointless word, isn't it?

I mean, if Intel has a 1Ghz ULV Dothan with 5W TDP and 2MB cache, they could put 16 cores and end up with a 16-core, 80W-thermal output processor which would, when executing massively parallel code, kick ass of just about anything.

Mind you, Intel could also put 4 dothan cores and end up with a 84W 4-cored processor<font color=red><b>*</b></font color=red>.

What is important in this whole story is who gets a dual-core processor out the door first, and how and with what configuration. Dothan has the added advantage that you don't even need a clock decrease to keep power down, that's why it's a good candidate.

In any case, because I don't understand jack about chip engineering and manufacturing (all I know is using them), I don't think I really know what will happen.... Interesting things are bound to happen anyway because of performance races! So why worry and speculate? I say let's enjoy it step by step, one step at a time... :smile: You're right to say, AMD could end up releasing a better dual-core eventually... if they do it faster, then intel has real trouble (here's that "if" word again)...

<b><font color=red>* - </font color=red></b> BTW, a 4-core dothan-based Xeon has been reported to be in development in Intel's India Labs, but is still a long road ahead.


<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 21, 2004 9:26:42 PM

yes dothan wouldnt have to lower clock speed to keep power down, but that would be the same for the low voltage opterons. i consider both of those chips very good candidates for dual core. prescott is not. opterons have the added advantage of having be designed to include the infrustructure for dual core to begin with lol.

besides, i doubt we will see dual core form either of them till next year.
July 21, 2004 9:55:51 PM

Absolutely, dual core from either one of them will only come in 2005.

Besides, AMD still has the 90nm transition to do.

And Intel still has to debug the 90nm chips (the "J" edition) and implement 64-bit functionality.

There are a few things on the to-do list before going dual-core on both companies.

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 21, 2004 11:23:44 PM

I'm not so impressed. A 90nm chip with 2 MB cache performs on par with a 130nm, 512kb part from AMD. Wow..I'm speechless :) 

A few things to consider:
1) Anand crippled all the cpu's equally (single channel, slow memory,..), which isnt unfair, but does give a bigger advantage to the huge cache of Dothan. Had he added a P4EE, I think the results would be far less promising.
1.5) upping the FSB and adding dual channel will do much less for Dothan than it would for the P4C, and to a lesser extend, the A64.
2) it remains to be seen how high Dothan can be clocked. Clearly, thermals aren't the problem, but other factors are much more likely to limit Dothan to clock speeds well below what is achieveable for A64 on a similar process. Loosen the thermals, up the Vcore, and ~2.5 should be within reach, but that will be less than even the initial 90nm A64's. 3+ GHz is out of the question IMHO.
3) dual core is nice and all, but not very different from SMP performance wise. How many people are running 2 way systems here ? Why do you think there arent any more ? A 2 way Athlon MP 2400+ is cheaper than a 3800+. Simple anwser: the benefit isnt there for >90% of the applications. Single threaded performance still matters much more on the desktop. Besides, by the time you'll see dual core "dothans", you'll see dual core K8's. You may well see the K8's earlier, either as opteron or Athlon FX as well.

In short: what is impressive about Dothan is its extreme small size and low power consumption. Great for mobile, not that relevant for the typical desktop. You can't just trade them for more performance.

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 22, 2004 1:16:58 AM

Quote:
In short: what is impressive about Dothan is its extreme small size and low power consumption. Great for mobile, not that relevant for the typical desktop. You can't just trade them for more performance.

Your vision messed?
1) Why would slower FSB benefit the larger cache? It theory it should hinder it as it did the P4 and A64.
2)Why is that, how could upping the FSB and adding dual channel do less than upping it on the P4 or A64. Every single piece of silicon that moved to dual channel and a faster FSB always benefited even if it was only marginal.
3) The CPU is designed around power-saving so upping the V-core would probably just aggravate the silicon. But hey you always seem to sound like you are an IC engineer so you must know :tongue: .
4) Dual core latencies will be far lower than that of a SMP system.

Quote:
In short: what is impressive about Dothan is its extreme small size and low power consumption. Great for mobile, not that relevant for the typical desktop. You can't just trade them for more performance.

Well considering it puts out near 1/2 of the thermal output an A64 does, doesn’t have an on die memory controller, or a screaming fast FSB and a shaky micron process. I think it holds out extremely well.

With considerations it has no SSE2 and will probably never have it means it will never make it “the” desktop processor for Intel. But nothing is out of the realm of possibly.

AMD should fear this silicon since clock for clock it does more work while putting out far less heat with less FSB and other goodies that give the A64 and the P4 the edge on it.

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 22, 2004 2:42:48 AM

Quote:

I'm not so impressed. A 90nm chip with 2 MB cache performs on par with a 130nm, 512kb part from AMD. Wow..I'm speechless :) 

You're completely missing the picture here, I'm afraid... The thing is that Dothan is currently completely geared towards lower heat output, and A64 as an architecture couldn't care less about it - it's geared toward speed. What happens to be the case is that Dothan, while still NOT having as a main objective performance, is on par with a highly performance-driven architecture while still mantaining its own merit in what it was designed to do: be a mobile solution.

While I understand your things to consider, I also don't think you're highly qualified (sorry 'bout that) to accurately predict to what extent Dothan can benefit from dual-channel memory and 1066FSB. Neither are we, for that matter, but I'm sure it should have an impact. Why else would Intel have rigged Banias and Dothan with a quad-pumped FSB? Because it couldn't benefit from it?....

Also bear in mind that most of Dothan's architecture is secret. So unless any of us actually works for Intel's R&D department, all we can do is speculate... and try to stay unbiased and with good will.

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 22, 2004 6:39:07 AM

well first of all, just because intel made a choice in design doesnt mean its gold or that it was a good thing, i never just trust either company that everything they impliment must be good cause they 'know better' we have seen thats not the case.

lets look at this antoher way, dont forget that the price of a pentium m on its own right now is about on par with the low voltage opterons, so if you compare it based on that, they are really close in wattage. if you want to compare dothan to desktop cpus, then you have to consider what ti would cost to build a p-m system if you wanted one, otherwise this whole review was useless. i agree dothan is an achievement, but only in the mobile arena. until we see desktop chips at reasonable prices, you cant compare it to the desktop chips, which can offer better support parts like ram and bus speed.

it would have been nice to see it compared to the 35w athlon 64 low voltage mobiles too.

is the dothan a success? yes definitely
does it have no competition in the low voltage area? yes it does

this review just brings up more questions and not enough answers for me lol. ill wait till i can see it on adesktop motherbaord.
July 22, 2004 6:50:44 AM

>Your vision messed?

Not really.

>1) Why would slower FSB benefit the larger cache? It theory
>it should hinder it as it did the P4 and A64.

A bigger cache goes a long way hiding slow I/O and high memory latencies. Thats what it is therefore. The faster the memory subsystem, the less a big cache will pay off. So 2 MB does wonders with single channel slow memory, but it will provide less of a benefit (relative to small cache P4s and A64s) with faster fsb's and memory subsystems. IOW, the P4 and (to a lesser extend) the A64 will benefit more from faster I/O than Dothan. If you don't believe that, just compare P4B scores with P4C and/or single channel versus dual channel. Pretty damn big difference, and bigger than Dothan will enjoy.

> Every single piece of silicon that moved to dual channel
>and a faster FSB always benefited even if it was only
>marginal.

Obviously they will all benefit; question is how it would change there performance compared to each other. As I pointed out, Dothan will most likely gain less. IOW, P4 and A64 suffered more from the I/O castration Anand performed than Dothan. Give all cpu's a 66 MHz EDO RAM interface, and Dothan may well be 2x faster than the 512Kb P4.

>The CPU is designed around power-saving so upping the V-
>core would probably just aggravate the silicon

It is designed to operate at low voltages, which typically hinders clockscaling. All cpu's I'm aware off, with maybe the exception of K8 (built on SOI) benefit substantially from higher voltages to achieve higher clocks. Do'nt tell me you don't know that..

> Dual core latencies will be far lower than that of a SMP
>system.

And why is that ? I don't see the difference.. in both cases both cores will share the same FSB and memory controller. Only intercpu (intercore) traffic will be faster for things like cache snoops. Don't hold your breath..

>Well considering it puts out near 1/2 of the thermal output
>an A64 does, doesn’t have an on die memory controller, or a
>screaming fast FSB and a shaky micron process.

TDPmax isnt anywhere near 2x that of A64 on the same process, they are in fact pretty close at the same clock, same process, especially if you take into account the power dissapated by the northbridge and FSB which is not included in the Pentium M numbers, but which is included in A64. And intels 90nm is just fine; compare Dothan to Banias and you'll see they did pretty well.

>With considerations it has no SSE2

Sure it has.

>AMD should fear this silicon since clock for clock it does
>more work while putting out far less heat with less FSB and
>other goodies that give the A64 and the P4 the edge on it.

As I said, its a very nice mobile cpu, but I wouldn't fear it as a desktop/workstation chip unless I grossly underestimate its clocking potential (which I think falls far short of A64s).

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 22, 2004 7:27:42 AM

>You're completely missing the picture here, I'm afraid...

I doubt it..

>The thing is that Dothan is currently completely geared
>towards lower heat output, and A64 as an architecture
>couldn't care less about it

Well, the A64 doesnt do too bad then in the power consumption department if it "couldn't care less about it". Its pretty damn close to Pentium M in terms of TDP at similar clockspeeds, same process nodes and roughly equivalant performance.

> What happens to be the case is that Dothan, while still
>NOT having as a main objective performance, is <b>on par </b>with
>a highly performance-driven architecture

Is it really ? The fastest $600 Dothan can keep up with a crippled bread and butter 2 GHz A64 that only has a quarter of the cache, and that is produced on an older process. On 130nm, Banias scaled to 1.7 GHz, A64 to 2.4. Want to compare them, with full fledged I/O and claim they are on par ? Or even close ?? Want to compare a 2.13 GHz Dothan with a 90nm Athlon 4000+ or FX55 ?

I thought not, so what you *are* saying is that this mobile chip could *perhaps* go toe to toe with the A64 *if* it is given a much higher clock, faster fsb, better FPU, dual channel, etc, etc. Which could all be true, but remains to be seen. Its your speculation, but I'm more sceptical than you.

> I also don't think you're highly qualified (sorry 'bout
>that) to accurately predict to what extent Dothan can
>benefit from dual-channel memory and 1066FSB. Neither are
>we, for that matter, but I'm sure it should have an impact

OF course it will have an impact; however, common sense tells me the raison d'etre of a L2 (or L3) cache is to hide memory latency. The bigger the cache, the less of an impact a slow FSB or slow I/O has. Vice versa, the faster the I/O, the less a big cache will help (think K8). You don't need any qualifications to understand this principle. Dothan was outfitted with a big cache for a reason: keep performance good even on slow (less power hungry) I/O subsystems in notebooks. A64 cache reduced because it has such fast I/O that the bigger caches barely made a difference. Now if you cripple the A64 (and much more even, the bandwith hungry P4C!) to make an "even" comparison with Dothan, you can't extrapolate these results to predict what will happen if you outfit all cores with an equally fast I/O. Dothan will benefit less than P4C, there is no way around that. How much less remains to be seen, but it will be less period.

>and try to stay unbiased and with good will

I tend not to lack either much if I dare say so myself, but feel free to disagree. But claiming two cores are "on par" when comparing the newest, fastest chip of one with a crippled, low clocked part produced on an older process is not my idea of seeing the picture or showing a lack of bias.

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 22, 2004 6:25:45 PM

Quote:
All cpu's I'm aware off, with maybe the exception of K8 (built on SOI) benefit substantially from higher voltages to achieve higher clocks

Isn't the P4E's build with Intel’s SOI technology as well? Also this core is built around low voltages which means is logic units will be running slim too. I really don’t see that particular silicon taking a likening the increased voltages and clock speeds since the core is designed around clock efficiency and increasing voltages changes the behaviors of the silicon logic.

Quote:
And why is that ? I don't see the difference.. in both cases both cores will share the same FSB and memory controller. Only intercpu (intercore) traffic will be faster for things like cache snoops.

On SMP systems there is quite some space between the cores, on a dual core machine it would be a matter of microns. I see the latencies being lower on the dual core systems in comparison to the SMP machines of today.

Quote:
TDPmax isnt anywhere near 2x that of A64 on the same process, they are in fact pretty close at the same clock, same process, especially if you take into account the power dissapated by the northbridge and FSB which is not included in the Pentium M numbers, but which is included in A64.

<A HREF="http://www6.tomshardware.com/cpu/20040201/images/cpu_hi..." target="_new">Here</A>
It states the power dissipation is near 84-89watts for the A64's, that is no where near the maximum 21watts from the current Pentium-M.

Quote:
And intels 90nm is just fine

It's no where near from perfected as Intel had its 0.13u process down.

Quote:
Sure it has.

Ya your right nice catch on that one, but it goes to say its performance is lackluster, and the "digital world" can't have a lackluster digital media processor.

Quote:
As I said, its a very nice mobile cpu, but I wouldn't fear it as a desktop/workstation chip unless I grossly underestimate its clocking potential (which I think falls far short of A64s).

I don’t see clock speed being an issue the chip is going to be over 2 GHz in Q4. I think it’s a manufacturing process issue since the cores thermal specs have to stay in that 30watt area.

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 22, 2004 10:41:40 PM

>Isn't the P4E's build with Intel’s SOI technology as well?

Strained silicon, not SOI.

> Also this core is built around low voltages which means is
>logic units will be running slim too. I really don’t see
>that particular silicon taking a likening the increased
>voltages and clock speeds since the core is designed around
>clock efficiency and increasing voltages changes the
>behaviors of the silicon logic.

Pretty funny paragraph.. If you had a point I missed it, it sort of got lost in all the nonsense you're brabbeling.

>On SMP systems there is quite some space between the cores,

LOL.. yeah, true, I forgot about the "space" :) 

>It states the power dissipation is near 84-89watts for the
>A64's, that is no where near the maximum 21watts from the
>current Pentium-M.

*yawn*.. not again :(  I'm sorry, I'm getting tired of having to correct each and every statement you make. IF you want to believe A64 consumes 4x as much as Banias or even Dothan, be my guest. but you're off by roughly a factor 3x-4x.

Mobile A64s have a TDP of 35W @1.8 GHz, using a "TDP" that is much more conservative than Intels (Dothan has a TDPmax of ~37W using AMD's way of calculating TDP), that number even includes FSB and (most of the) northbridge power consumption, its achieved without fancy mobile technologies like cache gating and fsb gating, oh.. and on 130nm, not 90nm. Dothan beats K8 when it comes to average powerconsumption and low power states, (which matters a lot in mobile, but not on the desktop), but in TDP (which matters on the desktop and to achieve dual core) they are pretty damn close. Don't be surprised if K8 does even better on TDP than Dothan once it moves to 90nm.

>I don’t see clock speed being an issue the chip is going to
>be over 2 GHz in Q4.

Great, before that time A64 will be at 2.6.. even using 130 nm instead of 90nm. Dothan (90nm) may or may not reach 2.6 GHz as a desktop chip, but I don't believe for a second it could keep up with A64 on a similar process.

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 23, 2004 3:37:18 AM

Quote:
It states the power dissipation is near 84-89watts for the A64's, that is no where near the maximum 21watts from the current Pentium-M.



yet you cant deny that the mobile athlon 64's at 35W and the opteron EE line at 30W are that high, they can both compete agressively against dothan for low voltage... you cant just exclude those two form this comparision.
July 24, 2004 2:22:34 AM

Quote:
Pretty funny paragraph.. If you had a point I missed it, it sort of got lost in all the nonsense you're brabbeling.

The start reading what I type then, when you increase voltages you increase them on a "global" scale on the processor. Logic is very sensitive about voltages, with considerations that logic usually in very dense transistor counts and high draws in comparison to cache.

Upping the voltages on a processor that is designed to run slim will undoubtedly cause problems with the logic, plain and simple. When you OC what do you think goes first, the cache or maybe the prefect engine perhaps?

Quote:
*yawn*.. not again :(  I'm sorry, I'm getting tired of having to correct each and every statement you make. IF you want to believe A64 consumes 4x as much as Banias or even Dothan, be my guest. but you're off by roughly a factor 3x-4x.

You should go to sleep if you’re yawning. If you want me to believe otherwise find some solid thermal specifications on the A64. With considerations that the block on that chip is just as large as the P4's and RPM's are near the same, I just don’t see people running 40-50 on load on those coolers, running CPU's that aren’t putting out 60-90 watts of heat.

Quote:
yet you cant deny that the mobile athlon 64's at 35W and the opteron EE line at 30W are that high, they can both compete agressively against dothan for low voltage... you cant just exclude those two form this comparision.

Now we are talking what’s the performance of a mobile A64 vs. a Pentium M clock for clock watt for watt?

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 24, 2004 3:20:54 AM

i frankly dont knwo what your trying to compare....

what is mroe important? wattage? performance? best ratio?

if its performance, then if you compare the mobile ahtlon 64 and the low voltage opterons versus the dothan cpu, then that would answer the performance question. then if you get the wattage numbers, then you add that to the ratio. im telling you though, the opterons would probably have the ebst performance to wattage ratio.

frankly i dont knwo what the squabble is about, if its just low wattage, thats misleading. doth's are good, but they wont see any true potential til they make it to a desktop with all the bus and ram that desktops have.
July 24, 2004 10:59:51 AM

>pping the voltages on a processor that is designed to run
>slim will undoubtedly cause problems with the logic, plain
>and simple.

Plain and simple nonsense. An (U)LV chip is typicaly a cherry picked part that happens to run on a lower voltage. Think mobile 2500+. These chips run just as happily with the higher voltage of their "desktop counterparts" (same chips, just binned differently), and almost always, at a higher frequency. Its just that there is no "desktop" PM yet, but the logic holds just as well.

Dothan is built on the same process as Prescott, there is no reason to assume its transistors could not withstand Prescotts Vcore. In fact, afaik electromigration is more dependant on temperature than voltage, so I wouldn't be surprised if Dothan could handle an even <i>higher</i> Vcore as Prescott, since it will probably run cooler as Prescott at the same voltage. How much extra clockspeed that would bring is another matter entirely though..

>If you want me to believe otherwise find some solid thermal
>specifications on the A64

<A HREF="http://www.amd.com/us-en/assets/content_type/white_pape..." target="_new">http://www.amd.com/us-en/assets/content_type/white_pape...;/A>

Page 24, 35W TDP @1.8 GHz. Including memory controller and hypertransport. Using a way to calculate TDP that is not directly comparable to intel (AMD uses a TDPmax, intel a TDPtypical).

Up Dothans FSB to 800 MHz to match A64's performance, include dual channel memory and add the power the memory controller requires, use the same way to calculate TDP and you're looking at two similar figures. Oh, did I mention the A64 numbers are for 130nm ? Dothan shines for its low average powerconsumption and extremely low power consumption in sleep and deep sleep modes which makes it a terrific mobile chip allowing great battery life, but for maximum power consumption, it is not in a different league as A64 using the same premises.

>I just don’t see people running 40-50 on load on those
>coolers

Indeed not. The last 3000+ I built would not exceed 39°C under load.


= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 24, 2004 6:25:28 PM

Quote:
Plain and simple nonsense. An (U)LV chip is typicaly a cherry picked part that happens to run on a lower voltage. Think mobile 2500+. These chips run just as happily with the higher voltage of their "desktop counterparts" (same chips, just binned differently), and almost always, at a higher frequency. Its just that there is no "desktop" PM yet, but the logic holds just as well.

Dothan is built on the same process as Prescott, there is no reason to assume its transistors could not withstand Prescotts Vcore. In fact, afaik electromigration is more dependant on temperature than voltage, so I wouldn't be surprised if Dothan could handle an even higher Vcore as Prescott, since it will probably run cooler as Prescott at the same voltage. How much extra clockspeed that would bring is another matter entirely though..

The same process that’s your argument the same process means they should be able to handle the same voltages?

You are aware that different parts of the processor are made with different types of transistor gates. Different transistor gates handle different voltages, different speeds, different amounts of heat tolerances different densities the whole nine yards man.

So let me again state that the Pentium M's are designed around thermal output limits. Those limits will include core voltage and core draw. Those two variables alone rely heavily on transistor design implementation and electrical characteristics.

I am not saying it is impossible which I realized was what it appeared I was saying. The reality of the situation is if that core comes to desktop one day it will be severely redesigned to accommodate the variables that make a desktop processor different from a mobile one.

Quote:
Page 24, 35W TDP @1.8 GHz. Including memory controller and hypertransport. Using a way to calculate TDP that is not directly comparable to intel (AMD uses a TDPmax, intel a TDPtypical).


Here's a little formula I use to determine the max thermal output of processors.
DCD*V=TOmax
DCD =Direct current draw, in amps.
V =Max voltage of the silicon at load.
TOmax =Maximum thermal output.

64.8A * 1.42688V = 92.461824W 3.0 GHz P4C
71.5A * 1.41415V = 101.111725W 3.2 GHz P4EE
91.0A * 1.26805V = 115.39255W 3.4 GHz P4E

21A * 1.277V = 26.817W 2.00 GHz PM
21A * 1.277V = 26.817W 1.80 GHz PM
21A * 1.277V = 26.817W 1.70 GHz PM

Now since AMD is unable to break the laws of physics, it's a pretty safe bet that the formula I used for the P4's and PM's will work.

57.8A * 1.5V = 86.7W 2.0 GHz A64 (3000+)
25.2A * 1.3V = 32.76W 800 MHz A64 (3000+) Cool N' Quiet Mode.
57.4A * 1.5V = 86.1W 2.4 GHz FX53

As you can see your 35watts comes from an 800 MHz clock speed attained from Cool N' Quiet, not the full clock speed and our European friend so claims.

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 24, 2004 8:57:25 PM

Check out the AMD2800BQX4AX on page 24

<A HREF="http://www.amd.com/us-en/assets/content_type/white_pape..." target="_new">http://www.amd.com/us-en/assets/content_type/white_pape...;/A>

You forget that the current draw and heat production is dependant on the resistance of the chip. (I=V/R and P=I^2*R or (P=V^2/R)). Your equations basically mean nothing. The thermal characteristics of a chip have more to do with how efficiently current is routed through the chip than a simple max amps * voltage.

Dichromatic for your viewing plesure...
July 24, 2004 9:41:07 PM

... ok um the 35w mobile ahtlon 64's are low voltage, they dont exceed 35W, thats why they are rated that way. @ 1.8ghz, they dissapte 35W. i dont knwo why you think this would be some kind of lie on amd's part. the rating is at its full 1.8ghz speed. i can show you a prodcut link if you need that to believe me..
July 24, 2004 10:02:13 PM

Quote:
You forget that the current draw and heat production is dependant on the resistance of the chip. (I=V/R and P=I^2*R or (P=V^2/R)). Your equations basically mean nothing. The thermal characteristics of a chip have more to do with how efficiently current is routed through the chip than a simple max amps * voltage.

For the limits of the discussion I think the formula works fine. Adding ambient temp, leakage, pipeline depth, transistor count, heat conduciveness of the silicon, the silicon recipe, electrical noise, DC energy loss just isn’t needed when the numbers are within 15% of their real numbers.

But good point but like I said for the current discussion it works.

Quote:
i dont knwo why you think this would be some kind of lie on amd's part.

They aren’t its clearly labeled move down the chart and you’ll notice additional clock speeds with corresponding draw, and voltages. I also don’t know what’s so hard to understand with this the Athlon XP's put out their fair share of heat on 0.13u and then all of a sudden they have a chip that does near 2x the work per clock and are just as equally clocked yet they put out 80% less heat? Come on common sense guy’s new socket, new heat sinks, new power saving technologies, a better silicon recipe and some damned fine engineering IMO.

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 24, 2004 10:58:02 PM

Your equations are misleading as you’re applying power usage as if it’s power conversion to heat. By the conservation of energy you can’t put out more energy than you put in. Heat output will always be less than the consumption of energy. Even the most efficient home space heaters are about 85% efficient. The true travesty of justice is the seems to be that you took the 1600mhz numbers and labeled them 800mhz numbers.

For A64 3200+

2000mhz 1.4v * 42.7a = 59.78w
1800mhz 1.3v * 33.7a = 43.81w
1600mhz 1.2v * 26.5a = 31.8w
800mhz 0.95v * 11.4a = 10.83w

And those are for total energy. Thermal output should be at least 15% less.

Dichromatic for your viewing plesure...
July 25, 2004 2:23:30 AM

We are talking maximum thermal output and the numbers match up with the P4's so what changes for the A64's?

Min P-state 800MHz VID_VDD 1.10v IDD Max 15.3A
Apply the formula it comes to 16.83watts for the mobile processor at 800MHz.
Min P-state 800MHz VID_VDD 1.40v IDD Max 45.6A
Apply the formula again it comes to 63.84watts for the A64 3000+.

I am still not seeing what you’re getting at though, since those numbers fall into AMD’s thermal design power limits of 19watts for the mobile processors at min state and 89watts for the desktop processors at min state.

Considering a FX at 2.4 puts out 86.1watts at max thermal output and has an 89watt thermal design power limit. With margin of error I don’t really see the processors putting out much less than that perhaps at best case 20watts less for the FX line. But that’s being overly generous IMO.

With considerations that a 3.6 P4E at core voltage of 1.4v and power draw of 115watts puts out 161watts, that type of heat output is quite realistic, so I find it almost charming that you seem to believe A64’s don’t put out 60watts all full max thermal load. But either or you don’t have to believe the numbers but with the P4E’s leaking near 200 uA. I would almost say the estimates are generous.

Quote:
And those are for total energy. Thermal output should be at least 15% less.

A formula to back that up might convince me otherwise, but since I pulled 15% out of my ass to begin with I will be eagerly awaiting the results.

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 25, 2004 2:45:04 AM

...um and my link says what?
July 25, 2004 8:43:31 PM

The mobile processor yes yes I know it's thermal specifications. I was still argueing that the desktop models put out their fair share of heat as well.

So I think this is all cleared up perhaps another thread?

Xeon

<font color=red>Post created with being a dickhead in mind.</font color=red>
<font color=white>For all emotional and slanderous statements contact THG for all law suits.</font color=white>
July 25, 2004 11:03:24 PM

You're comparing apples to lightbulbs. AMD's specs span the entire product range, probably including upcoming 2.6 GHz 130nm parts. Is it surprising a 2.6 GHz 130nm desktop part has a considerable higher TDP than a 90nm 2 GHz mobile part ?

To compare at least apples to oranges, compare AMD's mobile A64 to Dothan, and you'll see that the mobile A64, using your math consumes up to:
27 * 1.2V = <b>32.7W @ 1.8 GHz</b>

If you consider that number includes FSB and dual channel memory controller, and its a TDPmax unlike intels TDPtyp I think its fair to say it is not in a different league as the P-M in TDP per performance, in spite of the fact this chip wasn't designed from the ground up for low power, and the fact its built on 130nm instead of 90nm.

I stand by my point, a 90nm hammer ought to be pretty competitive with Dothan at least in maximum power consumption for a given performance level, and I expect it to lead bya considerable margin in absolute performance. Average/minimum power consumption, I expect Dothan to lead still, making it a mobile chip of choice if battery life is a major concern.

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 25, 2004 11:05:59 PM

> Heat output will always be less than the consumption of
>energy

Ahm.. if the energy you put in is not converted into heat, then into what exactly ? its not like there is energy poured into potential energy, deformation energy or light or something. I think its safe to assume >99% of the electrical energy you put in is transformed into heat. If not, into what then ?

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 1:26:44 AM

ok now that makes more sense lol
July 26, 2004 5:16:40 AM

Ahm.. if the energy you put in is not converted into heat, then into what exactly ? its not like there is energy poured into potential energy, deformation energy or light or something. I think its safe to assume >99% of the electrical energy you put in is transformed into heat. If not, into what then ?


I think Schmide has got you on this one. Enegry is a strange thing if you have enough you can create matter. energy is released in many forms to produce the desired effect. by products can be any # of things light, sound, heat probably many more things, its never close to 100% effecient. You could argue how much light a cpu gives off but then how much noise does a tree make in a forest if nobody is around to hear it? I do not know lots on this topic probably very lttle but Schmide stating "Heat output will always be less than the consumption of energy" makes perfect sence to me. A fuel injected car is probabbly only 30% effecient a lot of the wasted energy is heat noise etc I would not be too suprised if a cpu lost a fair bit of energy trying to accomplish it's purpose.


If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.
July 26, 2004 7:33:36 AM

> I would not be too suprised if a cpu lost a fair bit of
>energy trying to accomplish it's purpose

Energy isn't lost, its transformed into some another form. AFAIK, CPU's don't radiate light, not a chemical reaction that "stores" it, no potential (height) energy, not any half significant radiation energy (which ultimately gets transformed into heat again anyway), not deformation energy and there is matter that is created either.. I'm really at a loss what else than heat it could be converted into.

> A fuel injected car is probabbly only 30% effecient

Yes, but unlike what Schmide claimed, electrical heaters are 100% efficient, no energy is wasted through ducting or combution, unlike gas/fuel heaters that may achieve his claimed 85% efficiency (off course generating and transporting electricty is far from 100% efficient, but the heater itselve *is*).

A CPU is just a fancy electrical heater, no more no less...

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 8:03:28 AM

Energy isn't lost, its transformed into some another form.

Yes exactly energy is energy. and its the transformation (that is really what energy is) where it gets lost producing unwanted by products like heat light sound. Honestly I do not know if cpu's give off light but i'd be very suprized if they did not, one might not be able to see the light cause its encased in silicone or it's very small but there none the less same with sound. Nothing is 100% effecient if it was we might get perpetual motion.

Re: Yes, but unlike what Schmide claimed, electrical heaters are 100% efficient,

Personaly I doubt it. Even a electrical resistance eliment gives off light and I'd bet some noise on a minute level. OK OK don't get the eliment so hot so no light or less light and less heat, But what about infred? light waves come in many forms. Its a kind of light wave a human cannot see, but it with the right equipment they can from many miles away and do not try and tell me the heat travels all that way. So that is wasted energy.

I am out of my eliment here :-) but I personaly doubt the only wasted energy by product of a cpu is heat.

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.
July 26, 2004 8:45:22 AM

>Honestly I do not know if cpu's give off light but i'd be
>very suprized if they did not,

LMAO ! okay, for laughs and giggles, let's assume this is true, and they do radiate light. Two things:

1) Since I remember cpu's that didn't require heatsinks, i can positively attest a CPU does not generate *anywhere near* the light of a 5 milliwatt LED, and even if it did, we are talking about 0,00025% which is totally insignificant
2) Light ultimately gets converted into heat, since it is not persistant. Since no light escapes the cpu casing (or even PC casing if you prefer), it all gets turned into heat.

> But what about infrared?

Same story, and just as unlikely.

I do believe high frequency cpu's could generate some radiation, or electromagnetic waves (like X rays), but there the same story applies again.. these waves will bounce around and ultimately hit other elements, thereby converting their energy into heat. Granted, a fraction of that may well occur outside the cpu, or even outside the PC itselve, but you are talking about such insignificant ammounts that it really doesnt belong in a discussin about power consumption. For all practical purposes, a cpu converts 100% of the power it draws into heat. Its not like if the actual number where 99.99% that it would matter one damn.

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 8:58:47 AM

> but it with the right equipment they can from many miles
>away and do not try and tell me the heat travels all that
>way. So that is wasted energy.

oops, I missed this part. The answer is simple though, you can "see" heat with for instance infrared equipment, because every material emits infrared radiation (the hotter, the more). So your energy has to be converted into heat first, before it can radiate infrared radiation to become visible. As for the ammount of energy wasted, keep in mind even icecubes emit infrared radiation, everything does. It doesnt matter in this equitaion, you can not say a certain ammount of energy you put in is converted into infrared radiation and therefore, not into heat. Its the other way around, its the heat itselve that generates the radiation.

>I am out of my eliment here :-)

Yeah me too, I took my last physics course over 10 years ago :) 

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 2:38:14 PM

Hm... from what I can tell, you're right... the only possible energy emissions are electromagnetic in nature, and I doubt there's a lot to that anyway!

...which is why I kind of think Schmide's comment that a space heater could only have 85% efficiency, at most, is probably not quite correct... I'm not completely sure, but I do think so.

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 26, 2004 3:07:00 PM

>..which is why I kind of think Schmide's comment that a
>space heater could only have 85% efficiency, at most, is
>probably not quite correct...

I think he is confused with combustion/gaz/oil whatever heaters where some energy (heat!) gets lost through the exhaust, and the combustion process itselve may not reach 100% efficiency (some material is left unburnt, so you waste energy). Electrical heater are ~100% efficient, they have to be..

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 3:13:39 PM

Exactly what I think, too. :smile:

...even gas or oil heaters can be more efficient than that... I once saw a gas heater with... 99.1% efficiency. Pretty impressive. Too bad you don't always want to heat up things, 'cause that's the easiest thing to do... Car engines, for instance, don't get much beyond 20% efficiency, at most...

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 26, 2004 4:09:19 PM

Heat it is mon ami, nothing else…. Energy, whichever form it is originally in, eventually turns into heat. You roll a boulder downhill, its potential energy turns into heat by friction. If you are not as lucky as you think, it smashes your house on the way and it stops. All of its energy turns into heat with the impact.

Any material whose temperature is above absolute zero radiates photons. Some people call it light. Unless the material is hot enough, you don’t see the light but it’s there. Others call it Infra-Red.

All CPU’s when they run have a temperature above absolute zero, therefore all CPU’s emit light (Prescott’s a little more though). Light ain’t an alternative to heat, but a result of it.

Anything that is hot emits a photon, which is eventually absorbed by a cooler thing, which increases the entropy of the universe, taking us slowly to a thermal death…
July 26, 2004 4:47:54 PM

> If you are not as lucky as you think, it smashes your
>house on the way and it stops. All of its energy turns into
>heat with the impact.

Are you sure ? I thought there was something called "deformation energy", but then my physics may be more rusty than yours...

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 5:07:31 PM

Hm... I think that was a joke... Or at least I hope so...

In any case, eventually, there are other forms of energy. For instance, electric or magnetic fields store energy; in addition to that, several other methods of storing energy (internal energy) exist. Then there's work, which ultimately goes to "deformation energy", another kind of internal energy. So while most of it does get turned into heat, P4Man, you have a point there. Other things exist.

Then there's also the possibility that the energy, in whatever form, will also only be converted to heat far, far away. Like in a nuclear bomb: the infrared emissions are enough to incinerate and heat up anything in vicinity (i.e. several km), but while they're travelling, they're not heat...

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 26, 2004 5:33:38 PM

Pretty much… Heat is the most basic form of energy and any form of energy eventually turns into heat.

My boulder on its way can use a part of its energy to change the formation of other materials by hitting them. However, this doesn’t mean that the energy is used up or lost per se. After the impact either the boulder or the deformed material is hotter than it was before …and the hotter cools down, the cooler heats up, until their heat content comes to the same level.

If you get down to it, we can argue about the timing of a form of energy’s transforming to heat, like when you use your muscular energy to move the boulder to the top of a hill, where you have to wait until it rolls back to retransform its potential energy to back heat but these things don’t happen in the world of CPU’s. They transform all the power they suck off of the power supply to heat…

After all, this is what you initially said, No?
July 26, 2004 5:42:56 PM

>After all, this is what you initially said, No?

Yes, on the cpu thing I'm not arguing, we agree. I was wondering about the boulder example though. Like I said, I seem to recall that when materials change their structure (because of an impact for instance), this "absorbs" energy, known as deformation energy. IOW, your boulder running downhill and not hitting anything will see 100% of its energy transformed into heat, but if it hits a styrofoam block that deforms, less energy would be converted into heat, the delta is required to deform the styrofoam. Well.. that is something I seem to recall, but I could be off... either way, this obviously doesn't apply to cpu's :) 

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 5:45:53 PM

> Hm... I think that was a joke... Or at least I hope so...

Man, you are breaking my heart. It’s not a joke… I am damn serious.


> In any case, eventually, there are other forms of energy.

Sure there are. But they all are transformed to heat eventually.


> For instance, electric or magnetic fields store energy; in addition to that, several other methods
> of storing energy (internal energy) exist.

You missed Enterprise’s anti-matter warp engines :)  For the record, electric energy, electro-magnetic energy, Infra-Red radiation, Ultra-Violet radiation, etc. are all the same type of “energy” if you will. They all are based on photon radiation which is also known as electro-magnetic radiation…. But they all turn to heat eventually.


> Then there's work, which ultimately goes to "deformation energy", another kind of internal energy.

Can you elaborate on this concept of internal energy? Do you mean to say potential energy?


> So while most of it does get turned into heat, P4Man, you have a point there.

Not most of them. ALL of them


> Other things exist.

Really? What are these “Other Things”?
July 26, 2004 5:56:25 PM

"I do believe high frequency cpu's could generate some radiation, or electromagnetic waves (like X rays), but there the same story applies again.. these waves will bounce around and ultimately hit other elements, thereby converting their energy into heat. Granted, a fraction of that may well occur outside the cpu, or even outside the PC itselve, but you are talking about such insignificant ammounts that it really doesnt belong in a discussin about power consumption. For all practical purposes, a cpu converts 100% of the power it draws into heat. Its not like if the actual number where 99.99% that it would matter one damn."

AFAIK energy cannot be created or destroyed it just changes form. There are many types of energy light sound mechanical chemical and of course heat. Heat seems to be a common by product when energy is being used or transformed. How sure are you on waves (encased) bouncing around hitting other atoms and converting to only heat energy. lets say you take 3 rooms totaly insulate them no light sound or heat can escape. Now put a 300 watt light in one room, 300 watt heating eliment in the other and a 300 watt speaker in the last. Give it 24 hours then check the temps in each room. I'd be inclined to think the temps in the room using a heater would be much higher than the other 2 with the sound room being the coolest.

Regardless I am sure most of the wasted energy in a cpu comes out as heat.I'm just suprized to think its anywhere near 99.9% heat as a by product.

If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.
July 26, 2004 5:59:46 PM

Erm, no, not 100% of all energy in the universe will eventually be converted into heat. Take, for instance, the energy that binds nuclei together. It can be released by a nuclear reaction, freeing energy in the form of heat, but before that, it's not heat.
Quote:
For the record, electric energy, electro-magnetic energy, Infra-Red radiation, Ultra-Violet radiation, etc. are all the same type of “energy” if you will. They all are based on photon radiation which is also known as electro-magnetic radiation….

According to quantum field theory, you are right. However, I was merely stating that photons are energy transmitters and as such aren't heat. And not all energy gets transformed into heat at all. I mean, if you carried your boulder up a hill, energy gets transformed into potential energy, not heat. As long as you don't roll the boulder down, it remains stored as internal energy.
Quote:

Can you elaborate on this concept of internal energy? Do you mean to say potential energy?

Internal energy refers to any kind of energy storing process that happens inside a system. Classically, heat would be one way to do that, but there are other kinds of internal energy as well, like potential energies, if you will. Ways to store energy exist aside from heat; an endothermal chemical reaction, for instance, actually decreases temperature. And ultimately, mass is also energy, but certainly all mass will not turn into heat.

What is obviously true is that when dealing with computer chips, all of the energy consumed will eventually turn into heat in the end, but this is not at all true for all processes. What if you emit a photon into space? It won't get converted into heat, and it's definitely energy.

<i><font color=red>You never change the existing reality by fighting it. Instead, create a new model that makes the old one obsolete</font color=red> - Buckminster Fuller </i>
July 26, 2004 6:39:21 PM

>AFAIK energy cannot be created or destroyed it just changes
>form.

Exactly.. now think of under what form a CPU would generate other energy than heat..

> How sure are you on waves (encased) bouncing around
> hitting other atoms and converting to only heat energy

Fairly certain, unless those waves would somehow be able to alter to molecular structure; which could "absorb" energy or even cause more energy to be released (think nuclear power). Neither is likely to happen inside a cpu though ;)  If it helps you grasp this, consider radar waves, and try this: go to a military airport, stand in front of the radar cone of a plane, ask the pilot to turn on its radar, and you'll feel exactly what I mean (you'll get literally fried by the microwaves).

> lets say you take 3 rooms totaly insulate them no light
>sound or heat can escape. Now put a 300 watt light in one
>room, 300 watt heating eliment in the other and a 300 watt
>speaker in the last. Give it 24 hours then check the temps
>in each room. I'd be inclined to think the temps in the
>room using a heater would be much higher than the other 2
>with the sound room being the coolest.

Assuming the speaker actually draws 300 watt of electrical power (wattage of speakers is kinda fuzy, depends on impedence and frequency,..), they will be exactly as hot/cool.

>Regardless I am sure most of the wasted energy in a cpu
>comes out as heat.I'm just suprized to think its anywhere
>near 99.9% heat as a by product.

Not sure if its "by product", its the only thing a cpu produces with the energy its fed. If anything is amazing, then its the enormous amount of current a cpu requires (>100 ampere for Prescott!) just to operate..

= The views stated herein are my personal views, and not necessarily the views of my wife. =
July 26, 2004 6:41:42 PM

> Erm, no, not 100% of all energy in the universe will eventually be converted
> into heat. Take, for instance, the energy that binds nuclei together.
> It can be released by a nuclear reaction, freeing energy in the form
> of heat, but before that, it's not heat.

We are going off-topic but whatever. There is no difference between my boulder which I brought up the hill against gravity (which increased its potential energy by moving it apart from the center of a gravitational radiation) and your nuclei where protons and neutrons stay apart and don’t collapse against the gullion or z-particle radiations. It’s all potential energy. Drop them in a black hole, you get your heat back when they are smashed (and please don’t start like Hawking, Wormholes, Black Holes don’t radiate,, etc).

> According to quantum field theory, you are right.
> However, I was merely stating that photons are energy
> transmitters and as such aren't heat. And not all energy
> gets transformed into heat at all.

Heat is vibration of molecules. Photons are sub-atomic particles and therefore are not and can not be “heat” anyway. They just transfer energy between atoms and molecules and make them vibrate faster/slower. But please come back to our mortal and corporeal continuum. We are talking about CPU’s. No?

> I mean, if you carried
> your boulder up a hill, energy gets transformed into
> potential energy, not heat. As long as you don't roll the
> boulder down, it remains stored as internal energy.

Jeez. Read my previous post. There is always the timing issue but not with the CPU’s. If you fuse the atoms of a Prescott, you get much more than 70 C. And this isn’t gonna happen until the universe collapses back for the next big-bang.

Anyway, let’s cool down. I have the feeling that we are boring the audience with things that they haven’t come here to hear about.
July 26, 2004 7:21:06 PM

Re: "If it helps you grasp this, consider radar waves, and try this: go to a military airport, stand in front of the radar cone of a plane, ask the pilot to turn on its radar, and you'll feel exactly what I mean (you'll get literally fried by the microwaves)."

I'm not suprized but I don't see how that is relevant. I'll take your word I might want kids one day.


Re: "Assuming the speaker actually draws 300 watt of electrical power (wattage of speakers is kinda fuzy, depends on impedence and frequency,..), they will be exactly as hot/cool."

So this sound like you are saying heat output is a constant when energy is transformed from any one type to any other type of energy or at least electrical energy. Common sense tells me a room will heat up more using a 300 watt heater over a speaker drawing a constant 300 watts. But I could be wrong. I'd just like somone to explain how 300 watts going in always produces the same heat output take a 300watt air conditioner sure it creates some heat in the process but not the heat a 300watt heater would.


If I glanced at a spilt box of tooth picks on the floor, could I tell you how many are in the pile. Not a chance, But then again I don't have to buy my underware at Kmart.
!