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

Planning to run one or 2 GTX 295s... anyone have experience with either of these?

CORSAIR CMPSU-850TX 850W ATX12V 2.2
http://www.newegg.com/Product/Prod [...] air%20850w

Thermaltake Toughpower W0178RU 850W ATX12V V2.2
http://www.newegg.com/Product/Prod [...] 6817153072


Right now I am leaning toward the Thermaltake

for 2 GTX 295s, a OCd Core i7 920, 2 velociraptors and 2 1TB drives, do you think 850w is sufficient?

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

I would recommend a Corsair HX1000.

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!

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).

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.

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.

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.

2 GTX285 is ~325W.

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

The other options I am looking at is:

ENERMAX REVOLUTION85+ ERV850EWT 850W
http://www.newegg.com/Product/Prod [...] 6817194041

(or the 1050w, but that could run up the power bill!)

OR

Antec Signature SG850 850W ATX12V
http://www.newegg.com/Product/Prod [...] 6817371018

FWIW, take Newegg reviews with a grain of salt. The HX-1000 is an excellent fit if you want modular and it falls within your budget.

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