SLI GTX 570's - Not Booting PC

[NitrousX]

PC not booting after SLI two Gainward GTX 570's.
The one I have already is a Golden Sample 570.
And the other I recently added is a GTX 570 Goes Like Hell and the PC will not boot up, the PSU is a Silverstone Strider 850w .

And the advertised amps that it supplies is 67 amps on the 12v Rail.
Minimum Amps for the GTX 570 single GPU is 38amps will the PSU need to supply 76amps to run it?
I have tested both GPU's and they both are working fine in single GPU mode.
I have checked all the cables making sure there are no lose ends.
And the Nvidia control panel recognizes both of them.

So I think it may be my PSU that might be stopping it from booting.
If I need a new PSU what are the official amps required for SLI and would be the recommended PSU for SLI GTX 570's thanks
Also on the spec page for the PSU the maximum amperage is 72amps at 100% full load.

[ZaO]

What do you mean exactly by "it's not booting"? Does it not even power on, or are you just not getting a signal on the monitor?

I'm not sure about that brand of psu btw. But from what you've said, it's struggling for amperage I'd say yeh. Be careful you don't blow it and your other components. If it's being pushed that hard to supply the amperage, well I wouldn't even try it personally.

[NitrousX]

thanks for replaying yeah basically when I press the power button it does not switch on at all.
I have taken out the spare GPU and left with one in the Rig. So you think I should purchase a new one then.
Do you have any suggestions in mind?

[ZaO]

thanks for replaying yeah basically when I press the power button it does not switch on at all.
I have taken out the spare GPU and left with one in the Rig. So you think I should purchase a new one then.
Do you have any suggestions in mind?

That's weird that it just does nothing at all when you try boot it with both cards in. Maybe that psu is clever and knows it can't handle the load so cuts the power really quick when you try boot it.
I mean if you know what the maximum requirements of those cards are and you know your psu can't comfortably handle it. Then yeh I guess you want to get something with a bit more juice. Power supplies are something I'm not quite as sure about as other components tbh. I wouldn't want to give you bad advice so hopefully someone else can help. But I will say that I generally see Seagate, xfx, corsair and ocz psu's recommended. Maybe if you start a thread in the psu section stating your needs and budget, then someone will help you?

Edit: Not sure about seagate psu's btw. I think it might be something with a similar name! Told you I'm not so sure with psu's lol...

[c12038]

Here is some info regarding your problem

GeForce GTX 570 in 2-way SLI
•A second card requires you to add another ~225 Watts. You need a 750+ Watt power supply unit if you use it in a high-end system (800+ to a KiloWatt is recommended if you plan on any overclocking).

For each other card (3-way SLI) that you add, just add another 250 Watts and 20A on the 12V rails as a safety margin.

Extracted from here http://www.guru3d.com/articles-pages...review,13.html

You are probably looking at a 1000w PSU for the GTX 570 in SLI something along the these lines http://www.amazon.co.uk/OCZ-1000W-Se...2991078&sr=1-1


Hope this helps

[NitrousX]

i did have a reply from the GPU manufacturer and they suggested that i would need 1200W PSU and they said their cards run at 40A each so i would need about 80amps in total to run here's the email from them:

''Hello Samuel,
Thank you for your request.

We recommend for one 570 GLH (same tdp as the 580) a psu with 42 ampere current rating on the 12 volt rails.
But this includes the cpu and the other components in a standard desktop system configuration.
Here you can see the power consumption in sli:

http://www.guru3d.com/articles-pages...review,14.html

We recommend for sli a power supply with 950 or 1000 watts and 80 ampere current rating on the 12 volt rails.
For the highest power efficiency under pressure we recommend a 1200 Watt psu 80%+.
Your 850 psu should work also but it is possible the 12 volt rails are unstable under full pressure.

Mit freundlichen Grüßen,
Best regards''

1200w sounds a a bit extreme would of though 100w would suffice so i thinking maybe the Corsair HX1050 it has 87amps on the 12v rail see here: http://www.cclonline.com/product/885...-Unit/PSU0393/ what do you think?

[jim]

It's absolute nonsense.

Have a look at this: http://hexus.net/tech/reviews/system...aphics/?page=7

[NitrousX]

so you think their going a bit OTT with the power requirements then?

[jim]

Yeah, totally, but that's nothing new. If dual 580 cards on an OC machine drew 630W at the wall, then you can be very confident that an 850W supply is over-spec'd. Quite significantly so. You can see this all over the web. Even very powerful machines tend to draw a lot less power than people would assume, and you need to see a review like the one above to see what they actually do draw.

One of the usual problems is that if a graphics card company says "a 650W supply is fine", and you buy a 650W supply for £20, it probably won't be fine. If they say "a 1kw supply is fine", even a budget 1kw supply will hopefully cope with 650W, and therefore they'll be fine.

If you're buying a quality PSU, then that no longer applies.

Point is, I'd be looking elsewhere. Or, of course, the 850W is just faulty.

[NitrousX]

yeah very weird in deed cos the official specs on the gainward site shows that GTX 570's need 38amps so they have added the extra 4amps for a safety margin. PSU faulty hmm idk cos I'm using the same rig with the PSU and it works flawlessly with 1 gpu i have not had no power issues with it. What I think maybe the case is that the two GPU's need more amperage than advertised as the very max amperage my psu can go up to is 72amps so it stops the flow of current to the rig until i remove the gpu. Before i switch on the rig.

Seeing as i might as well buy another PSU i was thinking of getting the corsair HX1050 it would be future proof, I would have all the power at my disposal and most devices are becoming more energy efficient and i have ton of devices attached to the rig and some more i might add in future what do you think?

[ZaO]

yeah very weird in deed cos the official specs on the gainward site shows that GTX 570's need 38amps so they have added the extra 4amps for a safety margin. PSU faulty hmm idk cos I'm using the same rig with the PSU and it works flawlessly with 1 gpu i have not had no power issues with it. What I think maybe the case is that the two GPU's need more amperage than advertised as the very max amperage my psu can go up to is 72amps so it stops the flow of current to the rig until i remove the gpu. Before i switch on the rig.

Seeing as i might as well buy another PSU i was thinking of getting the corsair HX1050 it would be future proof, I would have all the power at my disposal and most devices are becoming more energy efficient and i have ton of devices attached to the rig and some more i might add in future what do you think?

I only sorta glanced through previous posts there. But you need to make sure your psu isn't working 100% all the time. I always try to make sure my psu can very comfortably handle the job I am throwing at it. You don't want to be pushing it to the edge all the time as it is the most important part of your whole system. It has the power (no pun intended ) to destroy your whole computer! Also you've got the apparently controversial efficiency rating. Most good ones are rated at 80+. Now people will argue this, but I think that means that above around 80% load the psu is going to start doing a crappy job, to put it simply. Don't skimp on the psu whatever you do man. Make sure it is nicely within it's comfort zone when your whole rig is maxing out on power consumption.

Another thing to note when you say the HX1050 should be future proof. Well, most psu's should be as far as power consumption is concerned. Seeing as components are generally requiring less and less power to run all the time. If it can SLI/CF a couple cards now, then it should have no trouble doing so in a few years or whatever. Providing it's still functioning properly and they don't make any drastic changes with motherboard form factors or anything like that.

I have a Corsair HX1000W btw (A bit overkill for my current build, but I'll be getting another GTX 670 OC at some point). I bought it new and sealed off someone who actually got it sent back to them as a full replacement for the last one which they blew. If I remember correctly, I think they said they were running 2x 480 GTX's and 4 HDD's. Not sure about the rest of the setup. But I'm guessing they had an OC'd CPU and maybe some water cooling. Anyway, that gives you a little bit of an idea of what it can handle I guess. But more to the point - Corsair sent them a brand new replacement which I think is pretty cool

You can always try one of those PSU calculators as well. I'm not sure how good they really are, but they should give you a "Ball Park" figure, if that's the correct term. I tried a few of them and I think my rig (which has 2 mechanical, 7200rpm hdd's - you can see other specs on the left) only comes in at around 400-450W under full load. Sounds to low to me tbh. But then again, I've never sat down and worked it out properly.

Anyway man. Hope this is of some help to you

[jim]

I guess if you're considering tri-SLI in the future, then a 1KW+ supply is futureproofing :/

[NitrousX]

thanks guys yeah this PSU is 80 plus rated silver, it does say it can handle SLI. But i just think that these custom GTX 570's are very power hungry.
Yeah I have tried psu calculators in the past here is the supposedly required amps for my GPU's including my 2HDDS, 1 SSD and CPU OC 4.5Ghz.
728w with roughly 53.2amps see here:

[ZaO]

While we're on the subject. Would anyone mind linking a few psu calculators that they think are decent?
Sorry to hijack the thread mate Thought it might help us both though.

[jim]

That's because PSU calculators are usually nonsense. The one you've linked to is widely appreciated to be nonsense.

Regrettably, I don't know any decent ones. The best solution I've found is to check reviews that mention power draw, hence why I linked to the HEXUS review earlier.

[ZaO]

That's because PSU calculators are usually nonsense. The one you've linked to is widely appreciated to be nonsense.

Regrettably, I don't know any decent ones. The best solution I've found is to check reviews that mention power draw, hence why I linked to the HEXUS review earlier.

Yeh that's what I would normally do. Can't beat a real world test