Can a 850PSU cut it for 3 5870's? | Bitcointalksearch.org

bcpokey

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Quote from: keybaud on May 25, 2011, 09:17:51 AM

Quote from: pokermon919 on May 24, 2011, 06:16:47 PM

Currently running 1 5870 in my computer, plan to slap in 2 more and upgrading psu instead of building a rig until I decide if I would like to build another dedicated rig. Was wondering if people have done it and ran stable powering 3 5870's with 850 watt psu.

I have 3 x HD5870s and a 700W PSU, although it is a 80+ gold one. The power draw at the socket is 690 watts at full load, so the rig is actually using approx 630 Watts.

Uh, your PSU is 91% efficient at 90+% load? Nuh uh.

If you see 690 watts at the wall it is much more likely that you have 600Watts to the system or less. I still haven't had time to take my rigs down and swap my meter over to a triple 5870 system, but my 2x 5870 + 1x 5850 system is eating 555W from the wall on a 80+ gold 650, so probably like 480W delivered. Make sure to downclock your memory

Clipse

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Using a psu bonding clip, both psu's earth on the motherboard.

Just do some research about psu bonding and psu bonding clips.

pokermon919

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Thanks for all the input guys. I was thinking about using 2 psu's but I read another thread where a member raised concerns over having a common ground for both psus and not having a common ground can eventually fry something, mainly motherboard. For the person running 2 psu's, how long have you done that?

keybaud

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Quote from: pokermon919 on May 24, 2011, 06:16:47 PM

Currently running 1 5870 in my computer, plan to slap in 2 more and upgrading psu instead of building a rig until I decide if I would like to build another dedicated rig. Was wondering if people have done it and ran stable powering 3 5870's with 850 watt psu.

I have 3 x HD5870s and a 700W PSU, although it is a 80+ gold one. The power draw at the socket is 690 watts at full load, so the rig is actually using approx 630 Watts.

Clipse

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Quote from: ?? on ??

Quote from: Clipse on May 24, 2011, 11:32:50 PM

850w with 80+ rating using singlephase will work depending on rest of hardware used, however I found it a much safer bet and stabler taking gpu overclocking into consideration to go with the much cheaper Coolermaster 550w GX series by binding 2 of them for 1100w (cost allmost 1/3 of an actualy 80+ rated 1100w psu)

Using two psu might be cheaper, but an solid 850 is more than enough for 3.

Although I'm not against the idea, only reason why I would use two psu instead of one is if I'm trying to 4x dual gpu card with a couple 850w psu's on linux personally.

Only reason you shouldnt go with 2x psu is if you plan on using a small case and cant fit both in. Other than that there is really no reason, 2x psu helps alot a hell of alot more when you plan on overclocking everything from the bees knees to the queens eggs on your hardware.

When I said cheaper coolermaster psu, I didnt mean crappy coolermaster psu. There PSU's are simply not overpriced and just as solid in design.

Not to mention, you basicly confirmed it, 2x psu is cheaper and it offers you 1100w or lowest wattage guaranteed 528w per psu so thats 1056 vs 80+ rating on 850w that would be around 820w.

Clipse

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850w with 80+ rating using singlephase will work depending on rest of hardware used, however I found it a much safer bet and stabler taking gpu overclocking into consideration to go with the much cheaper Coolermaster 550w GX series by binding 2 of them for 1100w (cost allmost 1/3 of an actualy 80+ rated 1100w psu)

Basiley

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not "any" 850W-rated PSU, but PSU that conform ATX 2.2 at least and brand made and new.
while ATX 1.x PSU probably just blow you PC. as well as some ATX 2.0.2 PSU's.

Meatball

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Yeah, I agree. You should be fine. I have a Corsair HX850 running 3 5850's with no problem. Even at max load it's only drawing about 520 watts.

Of course, I've gone low power on all the other components, 35W CPU, no CD drive, low power HD, etc.

scifimike12

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Quote from: TurboK on May 24, 2011, 06:55:15 PM

Any 80% rated 850w psu should be able to run 3x 5870s just fine, as long as you don't run them next to some dual q9550s on a skulltrail board.

You do realize that efficiency has nothing to do with the quality of the PSU.

pokermon919

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Quote from: bcpokey on May 24, 2011, 07:10:39 PM

3 5870s on a sempron system with a single hard drive and a buncha fans use less than 600Watts while mining with the memory clocks turned down. Potentially under 500Watts but I don't have equipment sophisticated enough to fully test that yet so I wouldn't recommend it. A quality 650Watt PSU is all you need. 850 could run 4 or potentially more 5870s.

thank you very much

pokermon919

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Quote from: warweed on May 24, 2011, 07:06:32 PM

depends really post which your looking at ? like what the amp is per 12v rail

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139009

this one

bcpokey

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3 5870s on a sempron system with a single hard drive and a buncha fans use less than 600Watts while mining with the memory clocks turned down. Potentially under 500Watts but I don't have equipment sophisticated enough to fully test that yet so I wouldn't recommend it. A quality 650Watt PSU is all you need. 850 could run 4 or potentially more 5870s.

warweed

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depends really post which your looking at ? like what the amp is per 12v rail

TurboK

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Any 80% rated 850w psu should be able to run 3x 5870s just fine, as long as you don't run them next to some dual q9550s on a skulltrail board.

pokermon919

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Quote from: SgtSpike on May 24, 2011, 06:38:12 PM

As long as it's a GOOD PSU, like a Corsair TX series, Seasonic, etc, then yeah, you should be fine. A Rosewill 850w probably won't cut it.

Yea I was specifically thinking about a Corsair TX 850watt one.

SgtSpike

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As long as it's a GOOD PSU, like a Corsair TX series, Seasonic, etc, then yeah, you should be fine. A Rosewill 850w probably won't cut it.

pokermon919

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Currently running 1 5870 in my computer, plan to slap in 2 more and upgrading psu instead of building a rig until I decide if I would like to build another dedicated rig. Was wondering if people have done it and ran stable powering 3 5870's with 850 watt psu.

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