GTX580 SLI on 650 watts?

[VI3L]

I felt comfortable with my setup until I read this. I'm running gtx 480 x 2 and an i7 at 4.2 Hz on a Seasonic 850 W M12D (2 rails rated 40 amps each). It just cracks 600 W in Crysis DX11 on my UPS LCD screen, but the 480(s) are at stock clock and voltage. Are you overclocking your GPUs?

Yes I am overclocking them to 850/2200, also my system is really ludacris, 5 hard drives 4 ssds etc, stuff like that and when I said 800+ those were worst case scenarios. You're 850 watt seasonic should be fine. If you start getting crashes then you will know you have a problem

650 on the other hand, lol...

 

[lehtv]

I'm running gtx 480 x 2 and an i7 at 4.2 Hz on a Seasonic 850 W M12D (2 rails rated 40 amps each).

600/850 = 70%. You're fine

 

[houe]

the OP said he was going to do a mild oc though.

I said maybe I would do a mild OC.

Keep in mind the seasonic x-650 is 87.4% efficient at full load so the number I'll be looking for is 744 watts at the wall with my Kill-A-Watt meter. See http://www.silentpcreview.com/article986-page4.html

 

[Termie]

Tom's just tested an overclocked 580SLI system on an x760. See the bottom of this page: http://www.tomshardware.com/reviews/microatx-gaming-overclocked,3039-17.html

The system pulled 875w from the wall in stress-testing, and Tom's concluded it was just above the limit for use on the 750w-class PSU. In fact, they stated that the Seasonic 850w PSU was the minimum they'd use.

Using the x650 for this purpose, even if you had no overclock, is clearly not a good idea.

 

[lehtv]

^ He's been told that about a dozen times. Do you think he'll change his mind now?

 

[houe]

What you're trying to do is like building a Ferrari with no engine lol... Better to build a "complete" Z06 that still runs fast

Wouldn't the 580s be the engine and the PSU be more like the gas?

 

[houe]

Tom's just tested an overclocked 580SLI system on an x760. See the bottom of this page: http://www.tomshardware.com/reviews/microatx-gaming-overclocked,3039-17.html

The system pulled 875w from the wall in stress-testing, and Tom's concluded it was just above the limit for use on the 750w-class PSU. In fact, they stated that the Seasonic 850w PSU was the minimum they'd use.

Using the x650 for this purpose, even if you had no overclock, is clearly not a good idea.

Thanks for the link! Keep in mind that is a heavily overclocked system basically maxing out a 760 watts Seasonic. If I don't OC I'm hoping to sneak under the 650watts. No its not ideal of course but I'm hoping it is doable.

 

[lehtv]

Wouldn't the 580s be the engine and the PSU be more like the gas?

No, the 580's and the PSU would be both part of the engine, since the engine both converts gas (in PC terms, AC power) to mechanical energy (in PC terms, DC power) as well as primarily determines how fast the car is.

What you're doing is building an unstable engine.

 

[Termie]

Thanks for the link! Keep in mind that is a heavily overclocked system basically maxing out a 760 watts Seasonic. If I don't OC I'm hoping to sneak under the 650watts. No its not ideal of course but I'm hoping it is doable.

No problem. I think the x650 is a great PSU, and if any 650w PSU is up to the challenge, this one might be. But as everyone else has mentioned, you're on a razor-thin edge here. If part of your thinking is that you'd just like to test out whether it's technically possible, I guess it can't hurt. Just have a watt meter handy the minute you fire up a game or stress test. At 89% efficiency at 100% load, that means you wouldn't want to pull more than 730w from the wall: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=169.

I also want to point out that in the Tom's test, they found that the at-the-wall draw of the system before overclocking was 779w, on the Seasonic 850 Silver (admittedly with factory-overclocked 580s). That would put the draw of this system almost exactly at 650w, and that's with a more efficient processor. That's why I personally think you're cutting it a bit too close, even without an OC. Here's the link to their load testing on the 850w PSU: http://www.tomshardware.com/reviews/microatx-gaming-overclocked,3039-16.html

I'd hate to have an x650 go up in smoke...it's an absolute gem.

 

[TakeNoPrisoners]

Thanks for the link! Keep in mind that is a heavily overclocked system basically maxing out a 760 watts Seasonic. If I don't OC I'm hoping to sneak under the 650watts. No its not ideal of course but I'm hoping it is doable.

Oh boy, you are still going to do it, after ignoring all of our advice. Have fun blowing your PSU up.

 

[BoomerD]

Geez....all you negative nancies...

Houe, go for it...it SHOULD work, right?

Please report back with your results.

 

[TemjinGold]

The thing is, it's going to work and he will think we are wrong. We'll just see him in the Computer Help forum in 3 months posting, "Help, my computer stopped turning on one day and I don't know why!"

 

[BoomerD]

The thing is, it's going to work and he will think we are wrong. We'll just see him in the Computer Help forum in 3 months posting, "Help, my computer stopped turning on one day and I don't know why!"

Of course, it won't be because he overloaded his PSU...it'll be something else completely.

 

[Spikesoldier]

even with a 100% efficient PSU 650W and 580SLI is not going to cut it.

 

[darckhart]

just posting to say that i will be amused at the results.

i know you have "special" gtx580s using "less watts" but here's my experience with "regular" gtx580 SC in SLI:

fortron fsp 700w: will have problems
pcpc 750w silencer: will have problems
corsair tx750 v2: will have problems
corsir tx950: seems to work

good luck with your "test"!

 

[lehtv]

^You actually went though three 700-750W PSUs before you acknowledged that it's not enough? Maybe houe will just RMA the X-650 when he runs into problems, thinking there must be something wrong with it. Then he'll just get another "faulty unit", sends it back, another "faulty unit", and then he'll never buy Seasonic products again.

 

[BoomerD]

^You actually went though three 700-750W PSUs before you acknowledged that it's not enough? Maybe houe will just RMA the X-650 when he runs into problems, thinking there must be something wrong with it. Then he'll just get another "faulty unit", sends it back, another "faulty unit", and then he'll never buy Seasonic products again.

Maybe he should just upgrade to Coolmax or Apevia PSU's...:biggrin:

 

[houe]

Guys calm down a little I'm not going to burn my PSU up. lol. I have a plan and I have a kill-a-watt meter. So I'll test and see if I'm within spec or not. If I'm out of spec then running a few minutes won't destroy the PSU. I'll simply stop the stress test and power down. I didn't know this was going to be so controversial. But I have received the advice I wanted - except for 1 or 2 people most people think its not going to cut it.

Also to save a few extra watts It is possible I could pull 3 of my 6 memory sticks and unplug a fan or two... That toms build also is running 2 water pumps which uses some power.

 

[Termie]

Guys calm down a little I'm not going to burn my PSU up. lol. I have a plan and I have a kill-a-watt meter. So I'll test and see if I'm within spec or not. If I'm out of spec then running a few minutes won't destroy the PSU. I'll simply stop the stress test and power down. I didn't know this was going to be so controversial. But I have received the advice I wanted - except for 1 or 2 people most people think its not going to cut it.

Also to save a few extra watts It is possible I could pull 3 of my 6 memory sticks and unplug a fan or two... That toms build also is running 2 water pumps which uses some power.

I don't think the 10w or so you'd save doing that will make or break your PSU. Now, once you've determined how far out of spec you are, it might make sense to do that for long-term use. At that point, though, I'd probably just get a new PSU rather than sacrifice memory, and more importantly fans, in a hot system like this one.

 

[houe]

Another option would to get one of these: http://www.frozencpu.com/products/56...ter_Cable.html and run the system off of two power supplies. My x-650 could run the system and one 580 and another power supply could run the other 580. Anyone have any experience with this type of set up?

 

[Termie]

Another option would to get one of these: http://www.frozencpu.com/products/56...ter_Cable.html and run the system off of two power supplies. My x-650 could run the system and one 580 and another power supply could run the other 580. Anyone have any experience with this type of set up?

Welll, that's an interesting concept, but if you were going to buy a new PSU, why not just get a single PSU that would work?

By the way, Newegg has the x750 for $130 right now...you could keep all your Seasonic goodness and give yourself a bit of breathing room: http://www.newegg.com/Product/Produc...82E16817151087. You probably wouldn't even need to pull any power cables, since everything's modular anyway.

As a sidenote, without a substantial overclock, your 580SLI could very well be bottlenecked by your CPU, even at your resolution. See HardOCP's admission of this in their article on Tri-SLI here: http://www.hardocp.com/article/2011/05/03/nvidia_3way_sli_amd_trifire_redux/1

 

[houe]

Welll, that's an interesting concept, but if you were going to buy a new PSU, why not just get a single PSU that would work?[/url]

I'm on a budget and have a 430 watt supply sitting around. Only have to buy a cable to link the two units.

 

[Yellowbeard]

Another option would to get one of these: http://www.frozencpu.com/products/56...ter_Cable.html and run the system off of two power supplies. My x-650 could run the system and one 580 and another power supply could run the other 580. Anyone have any experience with this type of set up?

I've done this plenty of times. With the gear you have on hand, that's the best option I've seen put forth yet. Benchmark guys run 2+ PSUs all the time. It works fine. You can even ghetto mod it if you don't want to buy that cable adapter thing. You use the "paper clip" method to jump start the 2nd PSU. Just do it a bit more permanent and insulate whatever wire you use to jump start the PSU.

 

[TakeNoPrisoners]

Guys calm down a little I'm not going to burn my PSU up. lol. I have a plan and I have a kill-a-watt meter. So I'll test and see if I'm within spec or not. If I'm out of spec then running a few minutes won't destroy the PSU. I'll simply stop the stress test and power down. I didn't know this was going to be so controversial. But I have received the advice I wanted - except for 1 or 2 people most people think its not going to cut it.

Also to save a few extra watts It is possible I could pull 3 of my 6 memory sticks and unplug a fan or two... That toms build also is running 2 water pumps which uses some power.

"If I am within spec or not."

Unbelivable.

 

[fffblackmage]

OP, if you're on such a tight budget, why are you risking damage?

Yes, OCP/OVP in a good PSU should prevent anything bad from happening, but why risk anything at all?

I've done this plenty of times. With the gear you have on hand, that's the best option I've seen put forth yet. Benchmark guys run 2+ PSUs all the time. It works fine. You can even ghetto mod it if you don't want to buy that cable adapter thing. You use the "paper clip" method to jump start the 2nd PSU. Just do it a bit more permanent and insulate whatever wire you use to jump start the PSU.

Would you need a independently regulated PSU? The gfx card should be just using the 12V line... so it just sounds like there's a potential for problems if the PSU is group regulated.