850W PSU - Corsair single rail or Thermaltake multi rail?

Thermaltakes are nice, but I would tend to go with Corsair instead. Corsair PSUs are some of the best I have ever used - right now, I'm running an HX-1000W. For 2 295s, you'll need a really good quality supply, and Corsair is among the best.
 

jamesgoddard

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nope - from my maths

2 GTX 295 = 325W each, 650W
OCd Core i7 920 = 150W
2 velociraptors and 2 1TB drives = 20W each, 80W (max load under spinup)
100W for other stuf (mobo - fans - DVD)

You're up to 1000W just about
 

theAnimal

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GTX295 is ~220W according to xbitlabs.
Velociraptors use less power than regular drives.

I would recommend a Corsair HX1000.
 
+1 for what theAnimal said!

jamesgoddard - Do not add the power reuirements of two single video cards to come up with power requirements for two video cards working in SLI or Crossfire mode. It doesn't work that way.

According to test reports actual power usage for two GTX295 video cards in tandem is about 340 watts and 29 amps at load.
 

pcbuildr

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I wasn't paying attention when typing.. I am only planning to use 2 x 285s, so a 850w should be more than enough. Nvidia's website is showing 183W for the 285.

I am trying to keep costs down and stay cool and quiet. This is for a workstation with casual gaming.

Thanks for the feedback guys!
 

assasin32

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I go with the Corsair, they make pretty good PSU's from what I heard. Thermaltake well I had less than satisfactory performance with them so far, though I own up to one of those problems being mine, and the other me and my friend trade blows on which was the itnitial problem I say PSU, he says mobo than PSU, either way I can't recommend them.
 

theAnimal

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Is your software able to make use of the GPUs?
 

850W should be fine. Besides, the Corsair is a BEAST of a power supply - it can handle more than most 900+ watt supplies.

For comparison, my system (i7 965 @ 4GHz, 4870x2, 2 velociraptors+1TB caviar black, 12GB RAM, and several assorted add-in cards [TV tuner, WIFI card, etc]) uses at most about 650 watts from what I've seen (and that's from the wall - factoring in an 85% efficiency based on the jonnyguru review of my PSU [the HX-1000W], the actual power used by the components was just 550 watts). That was tested by loading up the Everest random disk benchmark (hard drives seeking at max power), Prime95 LargeFFT (CPU and RAM), Folding@Home (both CPU and GPU clients), and 3dmark Vantage running on the extreme preset. All of these were run simultaneously, and the max power consumption I saw was only around 650 watts. Based on that alone, yours should easily run on an 850W power supply, especially if you don't overclock the CPU as much as I did (my 4GHz overclock uses 190W more power under Prime95 smallFFT load than it does at idle, so I'd guess that's basically entirely CPU power consumption).

 

pcbuildr

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cjl.. Thanks for the details... what Case and CPU cooler are you using? Did you have any issues with your cooler and ram clearance? Also, are you cooling your northbridge?

I have a Antec P180 that is not being used, but I was thinking to upgrade to Antec 1200 or Coolermaster Sniper or something since I want max airflow but still be quiet enough to sit on my desk without driving me crazy.

I have a build review thread at: http://www.tomshardware.com/forum/261782-31-core-workstation-gaming-build-final-decisions#t1901536 if you dont mind checking it out.
 
I'm using an Antec 1200, with a Thermalright Ultra 120 Extreme Black limited edition cooler (with this fan). There aren't any RAM clearance issues at all - the RAM does extend higher than the cooler could fit over, but the cooler stops short of the RAM slots. You would have problems if you tried to mount a thicker fan though (like a 120x38mm) - then it would extend over the top of the RAM. The northbridge is just cooled by whatever airflow it happens to get - I've debated adding a fan, but it is running just fine without one.
 

pcbuildr

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Awesome... I decided today to get the Thermalright Ultra 120, it was that or the Noctua, but in all the tests, the Thermalright seems to hold it's own.

I saw that the all copper version was available, but at $108 with no fan or 1366 mounting hardware, it is just too expensive and heavy to justify the premium. Did you lap the cooler? I was looking at crazy pc today and they have a lapping option for $19

I have some AS 5 from my last build so I will probably use that... I have ready that the ceramic is nice as well.

Do you find the 1200 to be pretty loud? Are you running the stock fans?

 
I didn't lap it, and I agree the copper is too heavy. I'd actually worry about motherboard damage with that one (it's over 4 pounds). I've debated lapping it, but for now, I've decided not to bother. It cools quite well without needing a lapping, so my laziness prevailed :)

Oh, and my 1200 is nearly dead silent, but I replaced all of the fans with these (which are still fairly loud at full speed), and added a Zalman 6 channel fan controller. With all the fans on low, it's almost inaudible, and with all of them on high, it is quite cool, though somewhat loud. At full load, though, the loudest thing in it is the 4870x2 - that thing has a vacuum cleaner for a cooler. At 50% fan speed, it runs 60C full load and is audible over every other component in the computer, even with all the other fans on high.
 

pcbuildr

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Yeah, I just don't game enough to justify the 4870x2.. Originally, it was on my list, but everything I read about the noise made me decide to go with the 285. If I end up using my existing P180 case for this build, I may be able to upgrade to a 295 tho.
 
It definitely is a beast, although it's surprisingly quiet at idle. It is inaudible at true idle, and when folding (reduced clocks, but not idle load), it is still pretty quiet. It's only when cranked up to full speed that it becomes ridiculous.
 

pcbuildr

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I like the corsair, but I really want a modular PSU since I may try to use my existing P180 case and space is tight.

Should I upgrade to the Corsair HX1000 (which currently has 10% doa 1 star ratings on Newegg) or the Enermax Revolution 1050w. ?

If I run 2 GTX 285 SLI and OC to 3.8, my wattage should be up around 700-750W.. Will this stress a 850w?

If not are their any good modular 850w PSUs?
 

theAnimal

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2 GTX285 is ~325W.

Some good 850W modular PSUs: Antec Signature & Truepower Quattro, Thermaltake Toughpower, Zalman, Seasonic M12D, Enermax Revolution, Silverstone Strider & Decathlon
 

pcbuildr

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Thanks for the feedback.. I took it a notch higher and picked up a Enermax Revolution 85+ 850w. Saved $75 by ordering from NCIX.