When to use 2 PSUs?

[Patch]

Deleted 1st thread because of erroneous title. Here goes again....

Blew one antec tpq 1200 OC already running 980x with tri-sli 580's under LN2. Everything pretty heavily overclocked with CPU at 6.09 ghz with 1.83v and all 3 cards at 1150/1150 with Gpuv of 1.38. Passed 3d03 with this, but "pop and smoke" from PSU when starting Jane in Vantage.

Someone had the good suggestion that I shouldn't use a surge protector (I had been) thinking it could limit the power input and starve the PSU. Sounds good to me, but checking my surge protector tonight it's rated for 1875W and I have run hairdryers through it for 20 minutes straight without trouble. The night of the blown PSU, the only other thing going through it was the monitor.

Now I have an Antec 1200 HC sitting here and I'm a bit leery of running all 3 cards on it alone. Even with stock cooling and volts, each card can go above 300W so I'm looking at an easy 1200W without much overclock.

Your guys thoughts? Add my TX650 to run one card? (It currently has fan duty run from another outlet). Wait for the 1200 tpq OC replacement from RMA to do dual duty? Risk running it all on the the 1200 HC?


In the meantime, I think I'll just do plain old 2 card SLI tonight.......

Edit: thanks for your input Kal. Advice noted.

[Hondacity]

after seeing elmors quad 580sli....and a 980...he was pulling 2kw from the wall...

i suggest dual psu for quad sli.....but for tripple..i think the hcp1200 has enough juice....

[Kal-EL]

I think using two cpu's is what was really on your mind :)

[Neuromancer]

While the PSU might run over its rated voltage, for how long is the real question. Hence the dual ppsu question.

What does the board/CPU draw with a little dinger card in it?

IF it is less that 650W... then I would just do that. and 1200 for the cards + storage to add a 3.3v and 5v load to it no matter how minor. (Dunno if that is a still a rule)

If not then 650W for one card, storage devices and 4pin PCIE expansion power . 1200 for the rest. Would add even more 5v load to the 650W and help keep its efficiency high.

I am not an Engineer and I did not stay at a HIexpress last night.

[Hondacity]

While the PSU might run over its rated power(wattage), for how long is the real question. Hence the dual ppsu question.

What does the board/CPU draw with a little dinger card in it?

IF it is less that 650W... then I would just do that. and 1200 for the cards + storage to add a 3.3v and 5v load to it no matter how minor. (Dunno if that is a still a rule)

If not then 650W for one card, storage devices and 4pin PCIE expansion power . 1200 for the rest. Would add even more 5v load to the 650W and help keep its efficiency high.

I am not an Engineer and I did not stay at a HIexpress last night.

980x can spike power ... as high as 800w..

[Neuromancer]

980x can spike power ... as high as 800w..

DAMN

So 650W for one card PCIE slot power and storage and 1200 for the rest.

Course thats only leaving 400W for 2x580s at worst conditions.

JEEZ

I know power reqs are exponentially increasing, so maybe drop it down to 5.8 GHz and only need 400W of power :) lol jk jk I would never suggest dropping an OC ;)

[DrNip]

If it were me and I blew one PSU already on my setup I would start using two PSU's because chances are next time you blow a PSU you might take some hardware with it!!! Damn if you lose that mint chip of yours.

[Chuchnit]

980x can spike power ... as high as 800w..


Got proof of that from a credible source? That seems hard too believe. I know shammy or nickshiih said they say as high as 600w in Antec's labs using super leaky A0's. If that was true I don't see vince only using two PSU's for the quad-SLI SR-2 rig. Not trying to put you down man, but that is a huge claim. I'd like to see the source fore thinfo.

[Hondacity]

we've seen it...

[Chuchnit]

What and all was the PSU hooked to? I'm guessing a minimum 24-pin and both 8-pin CPU? Is this measured from the wall outlet or did you find a way to isolate the CPU power draw and measure? If going from the wall you need to do the efficiency conversion based on that PSU at the given load. All I am saying is that 800w is a HUGE claim on power draw. We need accurate testing for proof on something like that. So far Antec tested 500w+ loaded and close to 600w peak. That was on one of those freaky ES chips too. I am inclined to go off those figures for now.

[Hondacity]

we were wpriming...imagine 12threads...

[Chuchnit]

we were wpriming...imagine 12threads...

Was this from the wall? These watts include 24-pin? Details please...... you are the engineer.

[Hondacity]

yes from the wall...

[Chuchnit]

So you start at ~800w from the wall. Effeciency numbers coming from jonnyguru TPQ-1200w test since I'm assuming this is the PSU you were using??

800w AC * 87.5% efficiency = 700w


That still leaves us with the power draw from the entire mobo INCLUDING overvolted and overclocked NB. Plus ram that is most likely overvolted/overclocked + PCI-E slot + SB + PWM and all other parts on the mobo that consume power. Stock X58 NB is like 35w or 45w. Who knows how it scales in power draw when overvolted/overclocked, but it can't be great since it's on 90nm process node. Just guessing, I'd say you are right around the majic 525-600w DC figure loaded with 6c/12t in wprime. That is still a HUGE power draw though! The point I'm trying to make though is that when talking about sizing PSU's and deciding on how many to run, the difference between needing 600w or 800w is huge.

[Hondacity]

antec hcp has 3 rails for the cpu...no need to worry.