Athlon with a 333 MHz FSB ?

G

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[ By choice - and partly by fate - I'm rather ignorant wrt hardware, so please have patience :). Clarifications are highly appreciated]

Hi there,

I'm on the lookout for building myself a rather powerfull PC I can use for DVD movie playback/MPEG-4 encoding/home video editing _but_ at a decent cost. After reading a bit some hardw. reviews I've set my mind to an Athlon XP on a VIA KT333 chipset motherboard (presently Asus A7V333), with an ATI Radeon 8500 DV.

The only probelms so far:

- I cannot yet find (reasonably priced) PC2700 memory that runs stable at low latency (CAS 2.0).

- Most important: AFAICT there is no Athlon out there yet that supports a FSB of 333 MHz (i.e. a system clock of 166 MHz. I'm still a bit confused when ppl talk about the clock or the 'double-pumped'/DDR ability of the FSB...is it like this ?). My question to the community is if there are any news wrt to the availability of such Athlons. Again, since I'm not very intrested in harware, over-clocking is not an option: I wanna be able to shoot a PC vendor if the CPU starts cooking...

TIA,

Yup
 

ath0mps0

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AMD has not yet released the Athlon configured for 166MHz (333 DDR) FSB. It will probably be sometime 3rd/4th Qtr. 2002 or maybe sooner (about the time Intel releases their 533MHz (QDR) FSB).

over-clocking is not an option: I wanna be able to shoot a PC vendor if the CPU starts cooking...
If your CPU starts cooking, it is YOUR fault and the vendor will not refund or exchange - even if you don't overclock.

That aside, any Athlon XP will run at 166MHz FSB if the multiplier is unlocked and lowered. The limiting factors are the chipset and RAM. The only chipset that seems capable of stably running at 333MHz DDR FSB is the Via KT333 - and the A7V333 is a good pick. PC2700 CAS 2.0 RAM would also be ideal. If you are concerned about the price of RAM, I would recommend you get a lower speed proc (i.e. AXP 1600+ instead of 2000+) and upgrade it later. Newer procs will come out and the prices will drop. Plus, if you fry your chip (something only an idiot without a good HSF would do), you didn't waste as much money.

I thought a thought, but the thought I thought wasn't the thought I thought I had thought.
 

ath0mps0

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P4 northwood and Intel 850 chipset for video editing.
I wouldn't; P4 has to go to 533MHz (QDR) FSB just to compete with Athlon in video editing. With a 333MHz (DDR) FSB, the Athlon would crush the P4 in video editing (IMNSHO, of course).

Trolling, trolling over the ocean green (it use to be blue, but now AMD's in da house!).

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bikeman

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The explanation to your confusion: asynchronuous clocks (or however you spell that ...)

This chipset is just supporting 333 MHz DDR-Ram, and does not need a 333 MHz FSB CPU. The CPU is connected to the VIA Nortbridge with its 133 MHz DDR FSB, the memory is connected to the same chip with a 166 DDR bus. Take a look at <A HREF="http://www.via.com.tw/en/images/KT333/KT333_BlockDiagram_web.jpg" target="_new">this picture from VIA</A>, which shows exactly what I just explained. The Nortbridge chips buffers and manages the data-streams between the both. Difference between the both buses is (I think and looked it up) that the memory interface is 64 bits wide, while the FSB data-bus is 72 bits wide. But it does make you think or doubt about the usefullness of that DDR-333 memory. I think the extra byte towards the CPU will not contain extra data, so actually (or should I say maybe) the FSB is bottlenecking the memory-subsystem. But it does work, apparently, your system gets a certain .5 to 1% performance boost (read <A HREF="http://www6.tomshardware.com/mainboard/02q1/020220/index.html" target="_new">THG's review</A> if you haven't done so yet), altough I think that improvement is made through other adaptations in the chipset.
Personally, I would not buy a KT333 (yet). The performance gain you get in comparison to the additional proce you have to pay ... I'd go for an KT266a-based solution, or, why not, an nForce based system. I think the <A HREF="http://www.asus.com.tw/mb/socketa/a7n266-c/overview.htm" target="_new">Asus A7N-266-C</A> is interesting. It's an nForce without incorporated GeForce2 MX400 that you wouldn't use anyway. It's price is reasonable, certainly considering the extra's you get, like an integrated Dolby certified surround sound solution and, what might me useful for your home-video-editing, a hardware MPEG2 encoder/decoder.
But OK, let's quit nagging about this. It seems as if I'm working for Asus. Ah, just one more thing. You seem not to be quite informed about the DDR-stuff. If you are, just skip this paragraph. DDR indeed does double the data rate at which a data is sent acros a DDRed bus. Most of the times, a bus is contolled by a clock signal that has a (approximate) block-wave form, with falling and rising edges. Classic buses sent data only on falling or on rising edges, depending on the implementation. DDR sends dat on both edges so doubling the data-stream. But don't ask me how a QDR-bus works. Actually writing this down made me wonder. Let's go and have a look in the chipsets-section.

Greetz,
Bikeman
 

ath0mps0

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The Athlon memory bus and CPU FSB are both 64bit data busses. Sometimes memory is 72bit, but that is for parity or ECC (error checking and correction) functionality. Running the two busses asynchronously (at different speeds) causes so much performance loss that the overall gain from using faster RAM is almost not noticable (1-5% performance increase). If you are going to purchase PC2700 RAM and run it at 166MHz (333 DDR), you are just wasting your money if you don't OC the CPU's FSB to 166MHz (333 DDR) as well.

I thought a thought, but the thought I thought wasn't the thought I thought I had thought.
 

bikeman

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Check out <A HREF="http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/24309.pdf" target="_new">this document on AMD's site</A>. It states :

<i>"2.4 AMD Athlon™ System Bus Signals

The AMD Athlon system bus is a clock-forwarded, point-topoint
interface with the following three point-to-point channels:
# A 13-bit unidirectional output address/command channel
# A 13-bit unidirectional input address/command channel
# A 72-bit bidirectional data channel"
</i>
on page 18 of the pdf or page 2.6 as printed on the pages. However I do wonder what the additional byte would be for (error detection?).

Greetz,
Bikeman
 

eden

Champion
I would ask you to wait a bit for the 166MHZ FSB from AMD if you need that 166FSB/166RAM.
Currently there is PC2700 RAM but I've yet to see any at CAS 2 functionality. This adds to the low performance boost that the KT333 gives over the KT266A. The latter however has been the fruit of gold from VIA, purely stable, best performer above any AthlonXP chipset. Most mobos have it now, and don't cost a lot for your convenience. I have the Epox 8KHA+, which was known to be the fastest until the Abit KR7A, but it costs too much IMO.

OTOH, since you do not overclock, not Northwood will make your life easier. AthlonXPs are best at encoding until the P4 reaches 2.2GHZ, and that my friend, costs over 500$ US, plus Mobo and RAM to add. With that you can get a little more performance, compared to something that costs 200$ or below, adding mobo and RAM. Saves you money to buy on other video equipment like software video editing, or more RAM!
So whatever AthlonXP you buy, you will be satisfied with, just don't spend on novelty stuff like a KT333, when no 166MHZ FSB without overclock, is available to show the real performance.

--
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G

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[First, thanks to all for the overwhelming response. As a newbie to hardw. teawking I have to admit some stuff is still a bit confusing but I hope it will clear out eventually]

Looking around (comparing reviews), I've came to the same conclusion: The VIA KT333 chipset would deliver its full potential when the FSB and the memory bus work _synchronously_, at 166 MHz. Most insightful in this respect was the "tech-report.com" comparison of chipsets for Socket A (they even used DDR266 CAS 2.0 memory with VIA KT333 chipset!):

http://www.tech-report.com/reviews/2002q1/via-kt333/index.x?pg=1

If I read correctly the conclusions, on an umodified Athlon FSB (266MHz DDR):

- The mem latency for DDR266 is lower than for DDR333 (penalties due to asynchronous/mismatching clocks, it appears).
- On same memory (DDR266, CAS 2.0), KT333 delivers more mem bandw. than KT266A and KT266. Pure and simple.

Unfortunately it appears that I have to swallow my preconcepions about OC-ing, get myself a hammer (sic!) and figure out how to unblock those pesky Athlon multipliers (it can't be rocket since, rite ? ;) Any "DIY for dummies" out there :) ?)

Anyway, since I think I'll wait a while before doing the jump (OT: I'm waiting for DVD+RW drives w. DVD+R capab,expected to be at the comming CeBit/Comdex) I'll just keep an eye out for further devels/price drops.

Again, many thanks for the insights.

Yup.

P.S.
a) The KT333 is a bit of a must since I really gotta have USB2.0 :))
b) Pentium 4 is a NO GO due to religious reasons :). No, just kidding, it really looks $$$ in terms of bang/buck. Morover apparently there is no chipset to really match it (i.e. get the best out of it). Please contradict me, with hard data, if possible.
c) MP is simply bull.

-- In order to get to heaven, turn right and go straight ahead --
 

eden

Champion
Why is the MP Bull?
Ya know, the price of it is much more logical and friendly than Xeons and it often performs at top performance. An AthlonMP 1.2GHZ was also better than a P4 1.7GHZ.
If you can get a dual, such as the Tyans, with AMD's new chipset, couple it with two MP1600 chips (no need for big MP2000 costs) with 512DDR, you can get a great system for encoding, much much faster than P4s. Just review total costs for now to see, and then look at dual CPU benches in video encoding to make sure you will pay that.
Yes the Hammer is too exciting, and I hope it lives up to the hype, including the rumoured price tag being the same as Athlons!!

--
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G

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Well, maybe I'm not 100% up2date with the latest tools but I am presently not aware of any MPEG-2 to MPEG-4 tool that can take advantage of a dualie system. Please feel free to contradict me.

Anyway, on a more constructive note:

<i> Originally posted by ath0mps0 </i>
...any Athlon XP will run at 166MHz FSB if the multiplier is unlocked and lowered
The only resources so far about OC-ing an Athlon seem to pertain to using silver laque to unlock the multipliers (close a bridge) and then increasing the core clock by setting the appropriate multiplier value in BIOS + core voltage (e.g. THG article+video). But, if i understood correctly, the idea here is setting the FSB clock to 166 MHz (possibly even _lowering_ the multipliers to get to the same level of core speeds ??!?! pls. correct me if I'm wrong..)

I'll be most grateful if someone could post some pointers clearing the matter. How about overheating, is it any issue (again, only increasing clock to 166 MHz, lowering multiplying factors, roughly same core speed,if possible). Would a "normal" HSF do ?

Thanks,

Yup
 

bikeman

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First of all, there are other motherboards implementing USB 2.0 without the KT333-chipset. (Abit NV7-133R (<A HREF="http://www.abit.nl/eng/product/mb/nv7-133r.htm" target="_new">specs</A>), for example).
Secondly, you do not need to scratch your precious XP to overclock it. You won't get it to 166 MHz, but a 140MHz system certainly is possible with a good cooler. But this approach to OC'ing (i.e. without changing the multiplier) does OC your entire system, including your memory and PCI-buses, which might compromise your system stability. But actually, I don't know noting about OC'ing. The fastest computer I own is a dual PII-300 with 288 MB RAM and a SCSI-II HD-system (of which I am really, really proud), and that thing even is not overclockable, so why should I learn about it?
 

eden

Champion
Overclocking AthlonXPs isn't as fun as Northwoods, and they have a very low OC potential currently. They've reached the peak of the MHZ now. No normal cooler can possibly do more than 66MHZ more. You'll need big HSFs, like the Swiftech MCX462, or perhaps the Volcano 7 which will automatically throttle its speed up by the case temp, so OCing won't leave the system VERY VERY hot.
Or else, use watercooling, the only way to really bust the speeds up. Even then, THG got their 1.66GHZ up to 1.86GHZ before it couldn't run any higher, AT WATER COOLING COLD WATER. However lower clocked ones like the 1.4GHZ AXP, can go up to 1.6GHZ or more quite nicely with not so much hassle.

The best thing I recommend? WAIT.
Very very soon, in about 2 weeks, the AMD Thoroughbred will hit the technology sector. It will be 0.13m, this means it will overclock almost as good as a Northwood, SCALABLY NOT MHZ-WISE. It will also allow you to buy a high speed one with no heat problems, as it will be much cooler thanks to smaller micron process.
Otherwise wait for the ClawHammer, where it will be a serious performer.

--
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Matisaro

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Ok, I have a solution which will avoid the need to unlock the cpu.

Purchase a cheap 1600+/1700+. Then purchase a gopod hsf(alhpapal8045 which uses quieter 80mm fans), then set the fsb at 166 without unlocking it. 99% chance you will boot and run fine at 2000+ speeds. And if not, you can then unlock the chip as origionally planned.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!
 

Matisaro

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Actually the xps have a decent oc potential, topping out around 1800 real mhz, which is not too shabby, however as you pointed out, you can get a 1600+ or 1700+ and max it out easily.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!
 

AMD_Man

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Or you can buy the dirt cheap Volcano 7, and then mod it to run at ~4000RPM.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor
 

FatBurger

Illustrious
Have you even looked at benchmarks? Encoding, video editing and Quake 3 are the three benchmarks that the P4 has always won at. An Athlon at 166MHz FSB would beat it of course, but that would requite overclocking.

<font color=orange>Quarter</font color=orange> <font color=blue>Pounder</font color=blue> <font color=orange>Inside</font color=orange>
Don't step in the sarcasm!
 

Matisaro

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The volcano is a 60mm hsf right?

Get the aplhapal8045 for 29 bucks, HUGE, and quiet.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!
 

eden

Champion
That was because it runs at 2.2GHZ. In no way is it any better, just because it is so far. Clock per clock it has no advantage in video editing, and it still requires a 2A GHZ to see some better encoding than the XP2000.

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bikeman

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Don't get the clock-per-clock thing started again. Take performance/price as a comparison-criterium. I guess then AMD wins, but still, if you take both top-notch procs, the P4 2.2a wins.
 

bikeman

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Don't get the clock-per-clock thing started again. Take performance/price as a comparison-criterium. I guess then AMD wins, but still, if you take both top-notch procs, the P4 2.2a wins.
 

eden

Champion
Yes but the price premium to get that 2.2GHZ for a slight advantage is no valid reason in any possible way.

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ath0mps0

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The only resources so far about OC-ing an Athlon seem to pertain to using silver laque to unlock the multipliers (close a bridge) and then increasing the core clock by setting the appropriate multiplier value in BIOS + core voltage (e.g. THG article+video). But, if i understood correctly, the idea here is setting the FSB clock to 166 MHz (possibly even _lowering_ the multipliers to get to the same level of core speeds ??!?! pls. correct me if I'm wrong..)
If you really want to push your system to its highest potential performance, you get the fastest chipset and RAM you can get. Unlock the multiplier and lower it significantly (down to say 7) - this removes the CPU as the deciding factor for the moment. Now, overclock your FSB synchronously - mem and CPU at same FSB speed - to get the highest FSB overclock you can maintain stably. The higher your FSB, the higher your total performance. Verify that your PCI/AGP dividers can handle this level of overclock: 5/1 PCI for 166MHz, etc. Your PCI should be running close to 33MHz and your AGP should be close to 66MHz (no more than 38/76). Anything too drastic on these speeds and your cards will become the inhibitor.

Up your multiplier to get your processor about to its original spec (AXP 1600+ 1400MHz @ 10.5 multiplier w/133MHz FSB >>>> 1417MHz @ 8.5 multiplier w/166MHz FSB). Run at this speed for a week or two under 24/7 load. This will help you tune for stability. After have completed this "FSB burn-in," you are ready to start increasing your multiplier - do this until your system becomes unstable and pull back a little. Continue the 24/7 burn-in to test for stability and tune as necessary. You have now found the sweet-spot for your entire system. You may find that due to the lack of granularity in the .5 multiplier increases that your CPU speed is a little lower than you'd hoped, but your system performance will be higher (i.e. 1800MHz @ 12x 150MHz FSB will be a slower system than 1750MHz @ 10.5x 166MHz FSB or 1780MHz @ 10x 178MHz FSB). If you are right on the brink, you can lower the FSB 1-3MHz to see if you can up the multiplier another notch. Remember, entire system stability and overall performance is better than the bragging rights of highest MHz CPU clock.

Oh, and one other thing: I usually keep a paper log of the BIOS settings I use and the changes I make during this process - that way if I have to clear the BIOS due to a lock-up, I know what settings caused the lock-up. There are other changes that can be made in the BIOS such as CAS latency, etc. that can increase performance even further - or cause more instability. I usually tweak these after I find the sweet-spot.

I thought a thought, but the thought I thought wasn't the thought I thought I had thought.