noob OC questions (N580)

[StonedPenguin]

Hi all.

I have oc'd my N580 to 900/1800/2150 @ 1.1V, This seems stable with max temps around 75c Furmark, 70c Gaming.

The question I have is in GPU-Z in sensors it says:

VDDC Current 8.0A (Idle), 45-48A (Load(Furmark))

Is this the Amps its pulling down the 12V rail? I was considering SLI but seeing as my PSU only has 60A on the 12V rail its no where near enough?

Do I need a PSU with ~90-100A on the 12V rail to run 2 N580s at the above oc'd speed? Or will they both not draw 45-48A each under load when in SLI, Is it drawing so much because its a single card?

Sorry for the noob questions, Help appreciated guys.

Cheers

 

[Cleeecooo]

A 100A on the 12v means it's a 1200W PSU!
A 1Kw PSU will easily run 580 SLI. A 850 would do so aswell.
If you have 60A on the 12V then you have a 720w PSU which, IIRC, is not enough for SLI (somebody correct me if needed)

 

[Krony]

I have pulled about 810w running a pair of 580's @ 940MHz so a decent 850w unit should be fine, if u wanted to have a bit more headroom then a 1000w would bw more than enough.

 

[StonedPenguin]

I have a Corsair TX750 that has 60A on the 12V rail. It is frustrating having to upgrade my PSU just for another 100w but I will probably go to 1KW.

Am I correct in thinking that the reading 'VDDC Current: 45-48A' on load in GPU-Z sensors, Is the readin taken from the 12V rail? If that's correct, How can a 850w (70A?) PSU be enough for sli 580's if its drawing 45A from a single card?

Sorry I might be way off the mark and talking crap, But thats how I seem to understand it?

 

[Krony]

Not sure where Gpu-z measures that from but it can't be just the card as the requirements for a single 580 are 600w and 42a on the 12v rail and that is for the entire system.

 

[StonedPenguin]

It says in GPU-Z when you hover over VDDC Current ''Current consumed at GPU Voltage level''

Idle = 7-8A, Load 44-48A. So if I had 2 580's using 44-48A's then I would need a Min of 90A, Ideally 100A? It does seem overkill at a 1.2KW PSU I suppose, I just want to make sure I'm working it out right...?

 

[Krony]

It's wrong, i'll ask on the TPU forum but there is no way a single gpu is pulling 45a.
Edit: Found a thread here explaining it.
But it's basically 1.072V*44.5A*3=143.112W

 

[StonedPenguin]

Thanks for clearing that up for me, Krony.

Appreciate it