power supply amount for this?

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Volcom13

· #3 · Nov 22, 2009

A solid 850W power supply should do you great.

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secureprivacy

Discussion Starter · #4 · Nov 22, 2009

then say you took off one of the 5850 cards, would a 650W suffice (With oc'ing the i7 to like 3.5GHz) ?

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YLDaryl

· #5 · Nov 22, 2009

Corsair 850 would be very safe but a 750 would do fine

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tofunater

· #6 · Nov 22, 2009

System will use less than 600 watts under peak load.
Pick anything in the 750 watt range and you'll be set for several upgrades

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benyu

· #7 · Nov 22, 2009

2

Quote:

Originally Posted by Junior79

I would say 1000 watts

uh.... no..

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LiNERROR

· #8 · Nov 22, 2009

a good 600w will probably never exceed 80%... and a good 750 will give you some overhead...

ATI even only suggests a 600w psu for crossfired 5850s... AND crossfired 5870s...

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Chunky_Chimp

· #9 · Nov 22, 2009

2

Quote:

Originally Posted by tofunater

System will use less than 600 watts under peak load.
Pick anything in the 750 watt range and you'll be set for several upgrades

This.

Founder of the Official Cooler Master ATCS 840 Owners Club and the Official Samsung SSD750/830/840/850/860 Owners Club

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Phaedrus2129

· #10 · Nov 22, 2009

I'd pick a quality 850W for the higher efficiency; efficiency at 60% load is generally a lot higher than at 85% load.

Corsair TX850W or TX950W are excellent PSUs for the money.

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Powelly

· #11 · Nov 22, 2009

2

Quote:

Originally Posted by Phaedrus2129

I'd pick a quality 850W for the higher efficiency; efficiency at 60% load is generally a lot higher than at 85% load.

Corsair TX850W or TX950W are excellent PSUs for the money.

+1

I've got a Corsair TX850W myself, and it is simply superb. I'm sure an 850W would suffice for your system (just to be on the safe side), but 1kW is simply overkill.

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tofunater

· #12 · Nov 22, 2009

Seriously. If hes not running intel burn test 24/7 while simultaneously running furmark, that pc will probably never exceed 500 watts. These new gpus are pretty damn efficient

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IntelConvert

· #13 · Nov 22, 2009

2

Quote:

Originally Posted by Phaedrus2129

I'd pick a quality 850W for the higher efficiency; efficiency at 60% load is generally a lot higher than at 85% load.

Corsair TX850W or TX950W are excellent PSUs for the money.

agreed^

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Sickened1

· #14 · Nov 22, 2009

2

Quote:

Originally Posted by tofunater

Seriously. If hes not running intel burn test 24/7 while simultaneously running furmark, that pc will probably never exceed 500 watts. These new gpus are pretty damn efficient

actually dual 5850's and an i7(if he overclocks) combined with everything else will exceed 500W.

Under load my rig uses over 500W. And i think the I7 uses more watts than my core2quad right?

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Chunky_Chimp

· #15 · Nov 22, 2009

2

Quote:

Originally Posted by Phaedrus2129

I'd pick a quality 850W for the higher efficiency; efficiency at 60% load is generally a lot higher than at 85% load.

Corsair TX850W or TX950W are excellent PSUs for the money.

If you want efficiency, then use the HX850 instead of the TX850. Better platform with higher efficiency.

Founder of the Official Cooler Master ATCS 840 Owners Club and the Official Samsung SSD750/830/840/850/860 Owners Club

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Phaedrus2129

· #16 · Nov 22, 2009

One thing people don't seem to realize is that power supplies derate over time as the PSU's internal components corrode. A quality unit won't degrade as fast as a cheap-o, but you still want to have a healthy safety margin if you plan to use the system for more than a couple of years. Also the greater the percentage of your PSU's rated wattage the hotter it runs, and the hotter it is the faster it degrades. Add in that you want to keep a decent efficiency and minimize noise levels, and it's prudent to go with a 750W PSU for a system that draws 500W. I'd say 650W minimum for dual 5850s, recommend 750W, and go for higher if you have the cash. I love the Corsair TX series' pricing:
650W - $100
750W - $120
850W - $140
950W - $160

Often with rebates. My point of view is, if you have the extra $20, why not go up the next step?

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tofunater

· #17 · Nov 22, 2009

Quote:

Originally Posted by Sickened1

actually dual 5850's and an i7(if he overclocks) combined with everything else will exceed 500W.

Under load my rig uses over 500W. And i think the I7 uses more watts than my core2quad right?

Really? Where do you get your power estimates from?

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Phaedrus2129

· #18 · Nov 22, 2009

Just remember, there is no downside to having an overkill PSU. Well, there is one; most PSUs get terrible efficiency at less than ~20% load, so if you're running an mATX dual core system with integrated graphics on a 1200W PSU you're gonna get worse efficiency than running it on a 450W PSU. But that doesn't apply in this case.

Having a larger power supply than the minimum necessary means higher efficiency under load (when efficiency matters most), cooler temperatures, less PSU derating, more stable voltages, less EM noise/ripple, lots of room for upgrades, and a quieter PSU fan (usually--exceptions exist). There is no downside.

And since the PSU is one of the most important parts in the system, if you're already shelling out the big bucks for 5850s and an i7 I don't see why a bit extra on the PSU would matter. So I'd recommend a quality 850W or greater from a quality brand: Corsair, SeaSonic, and PC Power & Cooling are my top picks.

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