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I've been wrong before....

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November 9, 2006 1:45:51 PM

I will no longer be making PSU recommendations for systems using the new 8800 series cards, there is a lot of controversy surrounding the power and current requirements and i surely don't want to point anyone in the wrong direction.
If you feel that your PSU is adequate for the situation then by all means please feel free to throw the switch............I'm out

More about : wrong

November 9, 2006 2:44:08 PM

I have my PSU plugged into a wall outlet. Plenty of power.
November 9, 2006 2:57:56 PM

Possibly not the best way to look at it :p  I have a 250watt generic PSU plugged into the wall too, but no way am I hooking it up to my 7800GT and overclocked D805. I'm not that dumb.
Related resources
November 9, 2006 3:03:13 PM

For what it's worth, the xfxforce.com list the minimum and recommended PSU levels for their cards.

The 8800GTS had a reccomended level of 600W, the GTX was 700W.

However the minimums for these was 400 and 450W Respectively.

I think I can get a GTS (PLENTY OF Horse Power) up and running at full throtle on my PSU. Even so - I would probably be fine with the GTX.

Cheers
November 9, 2006 3:15:14 PM

Quote:
For what it's worth, the xfxforce.com list the minimum and recommended PSU levels for their cards.

The 8800GTS had a reccomended level of 600W, the GTX was 700W.

However the minimums for these was 400 and 450W Respectively.

I think I can get a GTS (PLENTY OF Horse Power) up and running at full throtle on my PSU. Even so - I would probably be fine with the GTX.

Cheers


I reckon that a decent quality (Antec True Power or similar) 430Watt should be more than enough to power a single GTX, as long as there's only a single H/D and a DVD.
November 9, 2006 3:48:57 PM

Quote:
I think I can get a GTS (PLENTY OF Horse Power) up and running at full throtle on my PSU.
Cheers


:) 

1 horsepower = 745.7 watts
November 9, 2006 3:49:46 PM

Quote:
I reckon that a decent quality (Antec True Power or similar) 430Watt should be more than enough to power a single GTX, as long as there's only a single H/D and a DVD.


and you want a separate psu for your cpu

guys - this isnt funny - if you want to overclock your cpu and also your vid card and you intend to use a 8800gtx then please listen to the xfxforce guys - the 8800gtx is stronger than a 7950gx2 and that 7950gx2 is around as strong as my pair of 7800gtx cards in sli

and an antec 500 smartpower shat in its pants to try and power my cards with a 4800+ cpu and 2 gigs of ram

if you dont want to overclock then feel free to use any old psu - personally if i was going to buy a 8800gtx card id have been buying a 1000watt enermax galaxy or 1kw pc power and cooling psu to power it with - pointless investing that much in a card and not being able to enjoy it to the fullest if your machine keeps shutting down due to inadequate power
November 9, 2006 4:15:58 PM

Quote:
if you dont want to overclock then feel free to use any old psu - personally if i was going to buy a 8800gtx card id have been buying a 1000watt enermax galaxy or 1kw pc power and cooling psu to power it with - pointless investing that much in a card and not being able to enjoy it to the fullest if your machine keeps shutting down due to inadequate power


I've seen articles that claimed the DX10 cards themselves would require >300 watts and have also seen claims that load values of 140 watts are being measured on actual units in operation. That's like money for nuthin and your shaders for free. At this point, I'm just waiting to see what shakes out and since I'm not planning to be an early adopter, I can wait.

Can anyone out there tell me about having a problem specifically related to having a power supply with too much capacity?
November 9, 2006 4:51:09 PM

Here's the problem with using a PSU that is twice as big as it needs to be......
the PSU utilization factor drops back to around 50% and since Efficiency is Inversely proportional to Utilization then the efficiency goes up saving you money on your power bill which is apparently a bad thing.
November 9, 2006 4:53:26 PM

Quote:
Here's the problem with using a PSU that is twice as big as it needs to be......
the PSU utilization factor drops back to around 50% and since Efficiency is Inversely proportional to Utilization then the efficiency goes up saving you money on your power bill which is apparently a bad thing.


Yes... Bad... Must consume POWER!!!
November 9, 2006 5:03:26 PM

I concede - I used 'horsepower' in the generic meaning of 'getting the work done' but not the precise engineering definition.

My head is lowered for the shame I feel.

...... Ok - I am better now.

:) 

Cheers
November 9, 2006 5:43:25 PM

;) 
November 9, 2006 6:28:31 PM

Quote:

Can anyone out there tell me about having a problem specifically related to having a power supply with too much capacity?


Yes. Various and sundry people will endlessly harass you for wasting money and energy. They will refuse to acknowledge that you bought the larger psu for the reason of future expansion.
November 9, 2006 6:42:20 PM

Geez, I was hoping this card would be MORE efficent. I know it is vastly more powerful, but so is the Core2Extreme. No one can complain that the C2E is less efficent than it's predecessors. :?
-cm
November 9, 2006 7:08:41 PM

Quote:
if you dont want to overclock then feel free to use any old psu - personally if i was going to buy a 8800gtx card id have been buying a 1000watt enermax galaxy or 1kw pc power and cooling psu to power it with - pointless investing that much in a card and not being able to enjoy it to the fullest if your machine keeps shutting down due to inadequate power


I've seen articles that claimed the DX10 cards themselves would require >300 watts and have also seen claims that load values of 140 watts are being measured on actual units in operation. That's like money for nuthin and your shaders for free. At this point, I'm just waiting to see what shakes out and since I'm not planning to be an early adopter, I can wait.

Can anyone out there tell me about having a problem specifically related to having a power supply with too much capacity?

The crazy cost of an 850w or 1kw PSU is the problem I see!!!!!!!

Like you I'll wait and see first......
November 9, 2006 7:17:18 PM

Quote:
Here's the problem with using a PSU that is twice as big as it needs to be......
the PSU utilization factor drops back to around 50% and since Efficiency is Inversely proportional to Utilization then the efficiency goes up saving you money on your power bill which is apparently a bad thing.


Umm you confused me, haha So having a really high Wattage PSU with little Power requirements raises efficiency right ? And is better :oops:  ?
November 9, 2006 7:31:24 PM

Quote:
Umm you confused me

That was easy......
November 9, 2006 7:42:06 PM

Quote:
Here's the problem with using a PSU that is twice as big as it needs to be......
the PSU utilization factor drops back to around 50% and since Efficiency is Inversely proportional to Utilization then the efficiency goes up saving you money on your power bill which is apparently a bad thing.


I don't think that's true in application. A smaller PSU at 80% utilization should consume less power then a larger PSU powering the same load at 40% utilization. As you reach the upper limits of the PSU you loose at least some effeciency to heat and such, but bigger capacitors, larger power regulators, and bigger converters are inerrantly less effecient then smaller components of the same design and quality. Also, the bigger ones cost more. So there isn't much point in PSU overkill. You don't want to run it at peak load, and you want to leave a little room for upgrades, but capicitors age no matter how nice they are and power requirements change (12v, dual-rail 12v, SATA, quad rail 12v, etc) so trying to "future proof" your PSU by getting a much-higher-than-necessary wattage is a loosing proposition. You're just paying more money to have a less energy effeciency.

IMO if you needed to power a peak load of ~420watts and leave a little room for UGs you'd be far better off buying a high quality 550watt PSU then a lower quality 1000watt PSU both in terms of performance and energy effeciency.

If you're comparing the effeciency of a crappy 550watt PSU running a 400w load to a premium 1000watt PSU running a 400watt load... you're comparing apples to organges. Anyone who has been around for awhile (and saw the no-name brand PSUs be the first to hit the consumer market with ratings over 500watt) knows that the quality of a PSU matters far more on any scale then the maximum rated wattage and that is the unified message that should be presented to noobies, not "get a super-high wattage PSU".

Would be interesting to see some benchmarks that measure effeciency at the wall for more modern PSUs. THG did one awhile back, but it would be nice to put some of these 1000watt beasts to the test.

Oh, and from your sig, I thought I'd mention that there is no such thing as a "SATA II" device, that's just marketingese that the SATA-IO isn't very happy about as it's confusing and misleading. There are "SATA II extensions" but they are all optional and independent of eachother. You could have a 3gbit drive without NCQ and accurately call it "SATA II" capable if you wanted. You could say they are "3g+NCQ" drives, same number of characters even ;) 
November 9, 2006 9:22:22 PM

As an EE I would like to say both Mad_Dog has the most valid points in his debate with Flasher, but they are not mutually exclusive.

Having some overhead in a PSU is desired, given they are of equal quality or grade. The added overhead will provide:
Pros:
1) Room for future Expansion
2) Added efficiency through lower heat retention (larger rated PSU's should be designed to disipate more heat, thus run cooler at a given wattage)
3) Extrapolating point 2) above should also tell you that the PSU's cooling fan will be running at a slower/quieter rpm when it's running cooler, and the case in general will also be cooler (given the PSU dissipates heat out its fan not through the body to the case)

Cons:
1) Higher cost (shouldn't be an issue to anyone who could afford a 8800 anyway)
2) maybe larger/heavier

General rule of thumb is 30-50% overhead margin, but this is always a moving number as there are design trade-offs. If you look at power consumption of CPU and GPU under max loads you're talking approx. 150W + 380W then start adding for RAM, HDD, DVD etc.

Final analysis: with 8800gtx the PSU should be >750W
November 9, 2006 11:10:18 PM

If you all look at the manufactuer's websites, then you'll see that a 8800GTX requires 450w minimum, only when you go for SLI does a bigger PSU become a concern. My PC Power & Cooling 510w psu is actually a 650w psu, PC Power & Cooling assigns a psu its wattage based on contiuous (read: they leave the psu on for 24 hrs or more) wattage at 50 degrees Celcius, so you're actually getting a better PSU for your money if you by a PC Power & Cooling PSU. For those of you looking to upgrade, PC Power & Cooling makes a 1kw PSU with Quad rails and 4 PCI-E power connectors for Quad SLI setups. This PSU is about $500. Hope this helps.

------------------------

My System:

AMD 64 X2 3800+ OC'ed to 2.2 Ghz, BFG 7900 GTX 512 mb OC'ed, ASUS A8N-SLi Deluxe, 2 Gb Kingston Value RAM CAS Latency 2.5-3-3-6, Creative Labs Sound Blaster Audigy 4, Westen Digital 74 Gb Ratop ADFD, 2x Western Digital 250 Gb Caviar SE, 3x Thermaltake Hardcano 14 HDD coolers, Thermaltake Blue Orb II CPU cooler, Zalman VF-Cu 900 Blue LED VGA cooler, Thermaltake Extreme Spirit Northbridge cooler, and a PC Power & Cooling 510w PSU.
November 9, 2006 11:12:23 PM

Quote:
A smaller PSU at 80% utilization should consume less power then a larger PSU powering the same load at 40% utilization.


That depends upon the efficiencies of the two power supplies you're comparing. Look at the plot in this report in figure 7. For most of the units shown there, the efficiency peaked between 40 and 80% load and was pretty flat in that region. You can compare specific units and find significant deviations from the above plot but of the many I've seen, this is very representative of the average. So basically, your 40 to 80% comparison is simply not valid.

Quote:
As you reach the upper limits of the PSU you loose at least some effeciency to heat and such, but bigger capacitors, larger power regulators, and bigger converters are inerrantly less effecient then smaller components of the same design and quality.


This is going from bad to worse. As far as I know, you lose to heat at low loads too. Large caps are not necessarily less efficient than small ones.
November 9, 2006 11:12:36 PM

Quote:
If you all look at the manufactuer's websites, then you'll see that a 8800GTX requires 4500w minimum, ......


4.5KW. Dang!
November 9, 2006 11:16:49 PM

Woops!!!! 8O

Guess the 0 key got stuck :roll:
November 10, 2006 5:21:30 PM

Quote:
A smaller PSU at 80% utilization should consume less power then a larger PSU powering the same load at 40% utilization.


That depends upon the efficiencies of the two power supplies you're comparing. Look at the plot in this report in figure 7. For most of the units shown there, the efficiency peaked between 40 and 80% load and was pretty flat in that region. You can compare specific units and find significant deviations from the above plot but of the many I've seen, this is very representative of the average. So basically, your 40 to 80% comparison is simply not valid.

Quote:
As you reach the upper limits of the PSU you loose at least some effeciency to heat and such, but bigger capacitors, larger power regulators, and bigger converters are inerrantly less effecient then smaller components of the same design and quality.


This is going from bad to worse. As far as I know, you lose to heat at low loads too. Large caps are not necessarily less efficient than small ones.

Did you actually read that graph? The one on page 14?
You do bring up a good point, if this magical 40-80% still holds true for modern power supplies, so my example may have been off by 4%. However, if you actually READ THE GRAPH you will see that I am conceptually right, and if I changed my example to 74% on a smaller PSU vs. 37% on a larger PSU I would be completely right. I'm all for being corrected, but when it's a minor technicality that is wrong don't be an asshat and try to claim that I'm completely wrong. Of course you loose electricity due to heat at lower loads too, but when you start to reach the maximum thermal design load of the system you start to loose a greater percentage. But when you're under the designed electrical load of the system you loose electricity due to using power components that are too big for the job too.


1. The PSU with the highest tested effeciency in the 40-80% load range was a 220w model. The 250w model was the 3rd worst of the 8 models tested. Quality > Maximum rated wattage, like I said.
2. If you're comparing the best item in the list, the Rush 2 220w (second generation model of their 220w PSU) to the worst one, the 175watt "Cobra" you're comparing apples to organges, like I said.
3. Let's compare the best PSU to the highest rated PSU: Rush 2 220w vs. the Prowler 250w. A load of 80% on the Rush 2 is 176w at 75% effeciency, which is a 70% load on the Prowler at 72% effeciency. Quality > Maximum rated wattage > "lower load = more effeciency".
4. Let's try comparing the two PSUs with the biggest difference in rated wattage: the 50w Shrimp to the 250w Prowler. 80% load on the shrimp is 40w @ 72% effeciency the Prowler is at 16% load and 60% effeciency. Larger components are inherrantly less effecient, especially for smaller-than-intended loads. It's called entropy and capacitance. They electrons simply get lost. If you tried to use gold bars (perfectly clean and insulated, perfectly welded together) as a long run of speaker wire for lower power speakers your speakers wouldn't make any noise. The gold bars would absorbe and disperse the electrons before they got to the speakers because they are too big despite being one of the best conductive materials available.
5. Lets try the example that most closely fits the 80% vs. 40% example I orginally gave: the 175w cobra vs. the 80w shrimp. 80% load on the shrimp is 64w @ 72% effeciency. 36% load on the cobra @ 64% effeciency. This isn't the best example as the cobra is obviously a crappy PSU. The 80w Shrimp at 100% load still beats the cobra.
5. THis graph shows 4 models by the same manufacturer. Two 200w and two 220w. They are the ones that are almost identical. The other >200w PSU achieves it's best effeciency at 60-80% load, not 40-80% load. The Only other PSU that hits 40% and then is nearly level until 80% is an 80w PSU that kicks the crap out of a 175w PSU. This is hardly difinitive data.

So, the 40-80% range may be important (although it's probably more like 60-80%, and really PSUs are generally benchmarked for effeciency at 80% load), thank you for pointing that out, but as we can see *quality* is by FAR the most important factor when choosing a PSU and real-world testing is far more valuable than manufacturers ratings.

So, does anyone have any benchmarks of *current* PSUs? There's gotta be someone who is irrate enough at me going against the "more is better" enthusiast grain who is just itching to find benchmarks that show some nice beastly PSUs that actually have better effeciency at a wide range of given loads then some of the smaller ones that are available. Those are the gems we should be looking for and reccomending, not telling people "get a 1kw PSU". When we tell people that "uber wattage" is more important than quality, and they have a budget, they will buy a lower-quality PSU with a bigger number on it. Unless a gem of a high-end PSU can be found you're far better off speccing out your system, speccing out some possible future upgrades and buying the best PSU in your budget that will run that system at ~80% load then you are buying a lower-quality PSU with a big number on the label. It should be more reliable, have more stable rails, and should use less electricity. PC power supplies are fairly complicated and involve numerous design decisions that affect performance ranges and multiple components of varying quality and design. The maximum rated wattage of the unit is the first thing you shoud look at, but it is NOT the most important attribute of the unit.

Enthusiast and gaming PCs tend to have very large budgets but wether you're spending $600 or $6000 on a PC you should spend your money wisely... or just buy from a system builder.
November 11, 2006 12:47:01 AM

Quote:
You do bring up a good point, if this magical 40-80% still holds true for modern power supplies, so my example may have been off by 4%. However, if you actually READ THE GRAPH you will see that I am conceptually right, and if I changed my example to 74% on a smaller PSU vs. 37% on a larger PSU I would be completely right.


It's only numbers, right? You said 40 and 80 but after you see some data you decide you like 74 and 37? I see, you'll just massage your numbers till they say what you want. Maybe if you write another 3 page diatribe, you can convince yourself.

Quote:
But when you're under the designed electrical load of the system you loose electricity due to using power components that are too big for the job too.


So electrons look at a cap and determine it's too big for the job and then decide to not work as hard?

edit: accreditation fix
November 11, 2006 12:59:12 AM

Quote:
It's called entropy and capacitance. They electrons simply get lost.


What physics class did you learn this in?

Dude, electrons don't get lost. However, your little physics lesson here is TOTALLY lost.
November 11, 2006 9:04:44 PM

You obviously don't have the slightest clue how batteries, capacitors, and conductors work.

Resistance: Electrical components have resistance. That resistance converts electrical energy into heat energy and those electrons are lost.

Entropy: Batteries and capacitors convert electrical energy into chemical energy. Those chemicals decay/react over time into useless impurities or generating heat and release that energy (some are much better than others, for example a hydrogen fuel cell is could be considered a "battery" with near perfect storage capabilities as H1 and H2 are both stable isotopes, but it's nothing like the chemical batteries and capacitors we use in our electrical devices today). The more energy you are storing (using bigger capacitors) the more energy you will loose (as the rate of decay is determined on a chemical level a large capacitor and a smaller one of the same composition and design will loose charge in roughly the same period of time. The larger one has, of course, discharged more energy then the smaller one. This principal applies wether the caps are in use or sitting isolated). Those electrons are lost.

Capacitance: Capacitance is how many extra electrons a substance can store without being forced to pass them on (eh, this is a very vague layman explanation, but accurate). These electrons sit there and do nothing (eventually they are dispersed as heat or passed on, but slowly). They are lost.

You found a very old test that somewhat showed that I was off by a few percent and tried to use it to flame and say that I was completely off-base. And after I point out that the test only shows my *example* to be off by a small amount and actually shows my POINT to be accurate you then repeated your claim and somehow think that your ignorance about how resistance, entropy and capacitance work is evidence of my inaccuracy. You're an idiot AND and asshat.

"...electrons don't get lost." How freaking stupid can you be to say that in the context of a discussion of the efficiency of power converters? If electrons didn't get lost all PSUs would have 100% efficiency and neither of us would even be discussing this. Why do you think your CPU gets hot? It's not designed to do that on purpose, electrons are being "lost".

Look, you had one good point, but your data is old and really only shows me be slightly wrong about a minor tertiary statement I made. If you want to correct minor technicalities knock yourself out and thank you for your effort, but if you just want to flame people try to get accurate up-to-date information that actually shows that the person you're flaming is wrong.

For effeciency, stability, and reliability: PSU Quality > Maximum Wattage. If the components you're powering are insesitive to power quality and loss and can use as much power as you can give (a fan, heater, or lightbulb for example) them then you don't need to worry about this, but computers *are* sensative and will only use as much power as they need.
November 11, 2006 10:02:57 PM

Gotta go with Flasher on this one. Entropy, eddy current, current leakage, it's all relative. (10 years ET in the USN so I picked up a few things here and there :)  )

No stop fighting and let's move on. Don't encourage flamewars by calling eachother asshats, you asshats.
November 12, 2006 3:26:54 AM

Quote:

you cant go wrong with a quad rail;and thermaltake has some decent ones;but i am sure there are better ones.

http://www.frozencpu.com/products/3240/psu-191/Mushkin_...

http://www.frozencpu.com/products/4290/psu-209/SilverSt...


YOU'RE 100% wrong. Yes, 100% as in, you couldn't be any more wrong. Everyone should just take your suggestions and do the opposite.

PC Power & Cooling has a unit with up to 78A available on ONE 12V rail. Rail amperage is important, increasing the number of rails is a useless venture for performance computing, and it's only done to prevent fires from short circuits.

Say you toss a 4-rail power supply in you system with the following description:
12V RAIL 1: CPU Power (8-pin)
12V RAIL 2: Main Motherboard Power (24-pin)
12V RAIL 3: Drive/Accessory Power (4-pin and SATA)
12V RAIL 4: PCI-Express Graphics (6-pin) x2

And say each rail is 18A. That's going to be a total of 72A, nice eh? And say your CPU is 68W, your slots and RAM use 40W, your drives use 8W, and your graphics cards (two) use 360W (180W each). Do the math

12V RAIL 1: 5.7A
12V RAIL 2: 3.3A
12V RAIL 3: 0.7A
12V RAIL 4: 30A <---FAILED (18A rail limit)

So you had a system that pulled less than 40A kill a power supply that had 72A because one rail was overloaded. This is EXACTLY what sites like The Inq had experienced when running X1800 Crossfire rigs, and exactly why several sites recommend PC Power & Cooling EXCLUSIVELY.

Now, I have a BIG BEEF with you: I'm tired of freaking repeating this 1-2x per week, so STFU
November 12, 2006 3:41:57 AM

A-men. It freaks me out to see people who buy that $150, 700w PSU only to complain a few weeks later about how there system burned up the PSU. It's then further magnified in the way they talk about their system and how other people had this same PSU and didn't have any problems. Problemis they probably didn't read the firne print about how this guy has owned this PSU for only 1 day.

It's odd that no one has heard of PC Power & Cooling PSU's on this forum. I'll break down the rails on my PC Power & Coolin 510w PSU (650w max). It costs $225

Rail 1. 12v/18a 24-pin mainboard
Rail 2. 12v/18a 4-pin ATX
Rail 3. 12v/18a 4-pin molex for HDD's, opticals, ect
Rail 4. 12v/36a 6-pin PCI-E connectors for SLI systems

Hope this helps. :wink:

-------------------

My System:

AMD 64 X2 3800+ OC'ed to 2.2 Ghz, BFG 7900 GTX 512 mb OC'ed, ASUS A8N-SLi Deluxe, 2 Gb Kingston Value RAM CAS Latency 2.5-3-3-6, Creative Labs Sound Blaster Audigy 4, Westen Digital 74 Gb Ratop ADFD, 2x Western Digital 250 Gb Caviar SE, 3x Thermaltake Hardcano 14 HDD coolers, Thermaltake Blue Orb II CPU cooler, Zalman VF-Cu 900 Blue LED VGA cooler, Thermaltake Extreme Spirit Northbridge cooler, and a PC Power & Cooling 510w PSU.
November 12, 2006 3:56:19 AM

Hey, I used to hate PC Power & Cooling, back in the days when everyone was using a single 12V rail. Why? They charged too much. They used to modify the cooling in an FSP power supply and charge up to twice as much for it.

And you know how a lot of Dell cases use a standard PS/2 form factor power supply, but with the power plug hole blocked on the most commonly used side? HP and Compaq did the same thing a few times, Dell/HP/Compaq PS/2 form factor ATX power supplies were interchangable, but only something like 1 in 15 retail units were designed with the same plug location. FSP had a few, I believe Seasonic had a few, but the lower capacity versions disappeared and now you only find them in the workstation series.

Anyway, back then you could still find them, a standard $50 FSP unit with Dell/HP/Compaq plug location. PC Power & Cooling was already charging $80-100 for a slightly cheaper version of the FSP, and wanted to ADD $40 for the "Dell compatible" version!

Yeh, so they've been overcharging customers for a long time, but NOW it looks like they're the only company to have ONE BIG RAIL. That's too bad, because Seasonic and FSP are the Number 1 and Number 2 in manufacturer quality (nearly everyone else has their power supplies produced for them).

Yeh, so now we're stuck paying PCP&C prices because they're the only ones to give us one big rail...
November 12, 2006 4:12:55 AM

I wouldn't be so bold as to say that Seasonic and FSP are the best out there. I think personally that the PC P&C PSU's are better because they use industry feedback on what a PSU should be, then they go out and build that PSU (BTW they do this in the USA :!: ). Also I like how they rate a PSU based on its continuous output at 50C. This number is probably as close to real world for the temps inside a case as it can be. Also I love the fact that they don't use a modular PSU as this is where a majority of your loss of current occurs at the connection or plug-in.

No one on this forum needs to attempt Quantum theory, Calculus, or Physics when trying to describe a PSU. Because unless your a Ph.D., you all suck at theory, sorry. And no I won't try theory either because I've had to take physics 4 times and I still don't understand electrical theory as well as I should. So no opening of mouth to insert foot here!

Hope this helps :roll:

------------------

My System:

AMD 64 X2 3800+ OC'ed to 2.2 Ghz, BFG 7900 GTX 512 mb OC'ed, ASUS A8N-SLi Deluxe, 2 Gb Kingston Value RAM CAS Latency 2.5-3-3-6, Creative Labs Sound Blaster Audigy 4, Westen Digital 74 Gb Ratop ADFD, 2x Western Digital 250 Gb Caviar SE, 3x Thermaltake Hardcano 14 HDD coolers, Thermaltake Blue Orb II CPU cooler, Zalman VF-Cu 900 Blue LED VGA cooler, Thermaltake Extreme Spirit Northbridge cooler, and a PC Power & Cooling 510w PSU.
November 12, 2006 4:43:38 AM

I took physics once and got an A, finished the class at 97% on testing. I'm fairly certain I took Physics II too...I believe Physics was general applications and Physics II was mostly electrical theory...Hell I can't remember, but I never got anything below an A- semester grade in science-related coursework.

But hey, as to the other guy, I was just getting warmed up. You see, I knew that some power supplies were dividing the rails differently, with the drives and board power going on one rail, and the two PCI-E connectors getting 18A each. The problem is, that's only 216W per connector, and I'm hearing of new cards pulling up to 220W. Oh so close!
November 12, 2006 5:30:51 AM

Thank you for (once again) raising an insoluble issue.

Two pages of crap, and not one real post.
November 12, 2006 5:59:43 AM

I certainly hope nobody else confuses our facts for your opinion. I sure by now quite a few readers have been reminded of the advantages behind PC Power & Cooling's "one big 12V rail", as opposed to typical multirail units.
November 12, 2006 6:30:04 AM

Crap. Please show me a circuit design. Your opinion of what is a good psu is no better than a marketing mgr's opinion.

Show me the money.

Crap.
November 12, 2006 6:47:39 AM

I don't really have an opinion on that, just facts. I've read articles stating testing difficulties and resolutions (empirical data), and I do the math. Since number don't lie and I'm going to assume these publications don't lie outright, that's two sources of fact that should aid buyers in making a determination.

You're very opinionated on what constitutes fact, aren't you :) 
November 12, 2006 6:59:35 AM

What you meant to say was that you don't really have an answer, yeah?

Therefore crap.

I get tired of so called 'experts' that no nothing of circuit design telling us lesser mortals what is what.
November 12, 2006 7:02:51 AM

I see what you're trying to do here, you're trying to bury the useful info in ramblings, in effect making this thread the worthless crap you wanted it to be.

Denial is not a river :lol: 
November 12, 2006 7:16:16 AM

No, what I am trying to do is encourage some of the forum with actual PSU design experience to step up to the pitch... You, sir, are not one of them.

I used to be, but have moved on. Therefore I cannot qualify as to current designs, but I think that I could still vet a design in a few hours.

I get so tired of hearing "this PSU is great" or "this psu has @amps on @rails..."

Crap.

Until someonesteps up to the pitch, its all

Crap.
November 12, 2006 7:33:06 AM

Yes, let's all just throw empirical data out the window and say that numbers don't matter because the math isn't complex enough. The only crap in here is coming from you.

Even the noobies make good guesses sometimes, but you? I think you need a little less fiber in your diet.
November 12, 2006 8:03:38 AM

If it costs too much for a 1000w PSU, buy the little Thermaltake add on PSU (250w I think) and buy the Thermaltake 750w. That should give you 1000w for considerably less. Also, I don't get why everyone is trying to say the new cards require a "500w" or "600w" or whatever PSU. It depends on the SYSTEM! Find how much power the card uses MAX, and then add that on to whatever PSU size the rest of your system needs. I promise you that my SYSTEM will require a larger PSU with an 8800 than YOUR system might. Add 8 LED fans, a sound card, 3 hard drives and my USB keyboard and mouse, and fireflies in every molex connection; then weigh that against a single HDD, PS2 mouse and onboard sound with a mere 2 or 3 fans. My system without the card probably uses twice as much power. So quit trying to say "it requires this sized PSU" Do the MATH. Figure out how much the CARD consumes and your SYSTEM consumes. Don't guess at how much it all is together.
November 12, 2006 8:14:18 AM

I think everyone has heard of PC Power and Cooling. The truth is, my 620w Enermax Liberty is modular and doing just great running my X1900, just like it ran my 7800GT CO. It's also powering about 7 or 8 LED fans, 3 hard drives, a sound card, a G15 keyboard (which as backlit LED and LCD screen), a lighted Razer Copperhead USB mouse....yeah. Still goin STRONG. There are a number of great brands, and PC Power and Cooling loves to hype themselves up. Sure they're good, but they still use small fans...someone tell me that's not a little noisy. They're also quite ugly and have a huge tangle of cords. I'll stick with my good old modular Liberty and leave the big ugly loud expensive PSU's to you. If the DX10 cards need a more powerful PSU, I'll probably end up with one of those "cheap" Thermaltake PSU's. I'll do the shopping when the time comes. But until then, I can't really argue electrons, or chemistry or anything. I read reviews and use what works. And I ALWAYS buy a more powerful PSU than I currently might need. It helps to ensure consistent longevity, even if I never need the extra power. The extra energy it consumes is minimal. A few bucks a year maybe.
November 12, 2006 8:24:47 AM

Hey everyone? You're forgetting one thing...

I have an Enermax Liberty PSU, 620w. Also the 500w in my other 939 system...

They have dedicated PCI-E rails. They're even color coded to make sure you use the RED 6pin cable for the card and not your mobo. It makes big note of it in the manual as well, and you're kind of stupid if can't tell what it's for anyway. So while my other rails might only supply 18amps or so....it's plenty for 2 hard drives on one cord, or 5 case fans on one cord....I don't put all my components on one cord ever anyway...that's just stupidity and asking for trouble. If I recall, the manual even advises against putting all of your components on one wire.
November 12, 2006 10:17:20 AM

Quote:
Thank you for (once again) raising an insoluble issue.

So now this is my fault..........?
This is supposed to be a discussion board, a few people just need to learn how to discuss things, (peacefully).... 8O
I do feel bad though because i know i can start what seems like a relatively innocent if not slightly controversial thread and watch it fly out of control.
I feel everyone here has a point to make and should not be flamed just because someone else doesn't agree with their opinion, they are only opinions and everybody has one.
We must learn to take them with a grain of salt, and if we do not agree then it is our responsibility to provide contradicting proof of our resolve. Mankind is on a constant ever-changing learning curve and we are struggling to keep up with technology, let's try harder to do so w/o insulting another mans intellect.
We can't always be right , that's why the word "wrong" was created, i would like to thank everyone who has contributed to this thread, it is invaluable information that can't be found anywhere except in the minds of people like you.
AMEN
November 12, 2006 5:06:48 PM

Well hey, if we're going to be completely honest here, 18A should actually be barely enough for one PCIe Graphics connector and the 8800GTX, because the card does get some of its power through the slot. So a power supply with an 18A rail going to each 8800GTX should be barely enough for two of them. I'm not really comfortable with barely enough, hence I'll still push for the big single rail.

A few companies are even offering 19A on four rails, which sort of defeats the purpose of multiple rails: The idea behind multiple rails is to limit each to 18A, to reduce risk of fire in case of short circuit. I'm not too concerned with shorting out my power supply and having one or two leads catch fire however.
November 12, 2006 5:47:43 PM

With the big single rail, your 2x8800GTX at ~37A, plus your CPU at ~6A, plus your motherboard devices at ~4A and your drives at <3A, you should be able to get away with one of PCP&C's 750W units. And given that I rounded everything up, the Silencer 610W would probably be within its limits (but awefully darned close to its limits).
November 12, 2006 6:14:34 PM

No need to hurl insults here. However, some statements do require clarification (at least of their wording).
Quote:
.... That resistance converts electrical energy into heat energy and those electrons are lost.
Sorry, but electrons are not "lost" unless they meet antimatter, participate in radioactive decay, etc. They are still there, even if they have transferred some of their energy to other particles. Perhaps if you discuss things in terms of energy rather than particles it will be clearer. We start with a certain amount of electrical energy, and some energy does useful things according to the gadget's design, while some energy does non-useful things (e.g. is converted to heat, radiated as RFI, etc).

Quote:
Entropy:

Entropy is disorder. Not sure what direct relevance it has to batteries and capacitors.

Quote:
Batteries and capacitors convert electrical energy into chemical energy.

Perhaps a typo here. Batteries convert *chemical* energy into *electrical* energy (if rechargeable, they can also do the reverse). The function of capacitors *in general*, though, has nothing to do with chemical energy -- they're purely electrical devices that store electrical energy by separating electrical charge. One type of capacitor, the electrolytic capacitor, is manufactured ("formed") using an electrochemical process to create an extremely thin oxide dielectric layer on the surface of a metal anode, separating it from an electrolyte cathode. However, its function as a capacitor depends on the standard charge separation, not on chemical reactions.

Quote:
Capacitance: Capacitance is how many extra electrons a substance can store without being forced to pass them on ...
Actually, capacitance involves the storage of electrical energy by the separation of opposite charges, rather than a net storage of charges. It has two aspects: *capacity* to keep charges separated (whether electrons, ions, or whatever) and the *electrical potential* used to drive that charge separation. Rather than have a fixed limit to the amount of energy it can hold, the higher the voltage applied, the more a capacitor will hold, up to the various physical limits of the capacitor. In theory, for a capacitor of a given capacitance value, doubling the applied voltage will double the amount of separated charge (within the operating voltage range of the capacitor).

Quote:
For effeciency, stability, and reliability: PSU Quality > Maximum Wattage.

I don't think anyone can quarrel with that.

Refs: Here is a useful and accessable website on capacitors: http://amasci.com/emotor/cap1.html
November 12, 2006 6:35:04 PM

Wow, reading your response to Flasher's post makes me glad I didn't read Flasher's post, then I would have been battling on two fronts!
November 12, 2006 10:58:00 PM

Thanks for the clarification on capacitors.

Quote:
Sorry, but electrons are not "lost" unless they meet antimatter...
That would be electrons getting "destroyed", not merely misplaced. The last time I "lost" something I did not ponder if it had encountered anti-matter, although I may need to re-asses that possibility in the future. :p 

Eh, very true about batteries converting chemical energy into electrical energy and not necessarily the other way around. The recipes in commercially available batteries (Ni-Mh, Li-Ion, Ni-Cad, Alkaline, Lead-Acid) are all rechargeable, some are just designed to be far less likely to rupture their casing if you actually do it xD I can't think of any examples of chemical batteries that are completely unable to be recharged, but they would certainly still be classified as batteries.

Entropy is a central theme to the second law of thermodynamics and is extremely important to how batteries and capacitors work. However, I was just using it as more of a general term for how attempting to generate, store, convert, and use energy is inherently imperfect and wasteful. "...the idea dissipation of energy via intermolecular molecular frictions and collisions. In recent years, entropy, from a non-mathematical perspective, has been interpreted in terms of the "dispersal" of energy." http://en.wikipedia.org/wiki/Entropy The word does have a far more specific and useful meaning when dealing with the design of electrical systems, but that is far more fine-grained then I was attempting to be.
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