GPU Overvolting

[earwicker7]

My graphics cards give me the option of increasing the voltage to both the gpu and memory. I understand the basics of video card overclocking, but I've never overvolted before (I don't think my previous cards had the option). I'm guessing that the procedure would be to adjust the clock speeds and test for stability, then if you hit a stability wall, you boost the voltage a tad bit and see if this helps, correct? Are there any guidelines to use on how much you increase it? For example, do you not want temperatures over a certain threshold, should you never increase it by more than x amount, are there published tolerances, etc.?

 

[Sean W.]

How To: Overclock Your ATi GPU - Overclock.net - Overclocking.net

 

[Sniper_13]

will this guide apply to nvidia cards also? i couldn't seem to find a guide for Nvidia cards

 

[earwicker7]

Thanks!

 

[earwicker7]

So I ran Afterburner and GPUTool... once the temps started getting around 85, I started to pay attention to the fan graphs. Only one of the GPU fans (out of four) was doing anything at all! Any ideas on why this might be the case? After all, it wasn't only GPU1 that was getting hot, it was GPU1 through GPU4, and if only fan 1 was running, you'd think GPU2 through GPU4 would be way hotter (they weren't). Does this sound like a hardware thing, or is it possible it's just a glitch with the software reading the fan output?

EDIT: I've started a dedicated thread on the fan output at http://www.techist.com/forums/f10/afterburner-only-showing-one-out-four-gpu-fans-running-238050/#post1855481

 

[earwicker7]

One other thing... let's say I've reached my maximum temperature (I'm shooting for 85); would overvolting cause the temperature to lower? I don't know a huge amount about electricity, but I would think that with more voltage, the GPU wouldn't have to work as hard, so would run a bit cooler. Am I correct?

 

[patonb]

No, its complete opposite.. overvolting will increase your heat... more power equals more heat.

It works for both cpu and gpu, or anything.

 

[earwicker7]

Thanks for clearing that up!

 

[earwicker7]

Ok, so after altering my fan curve in Afterburner, my temperatures have drastically dropped without the noise being deafening... woohoo!

I'm starting to get a few artifacts, so I'm going to slightly overvolt the core voltage. How small should the increments be, and is there any maximum to avoid (similar to "you don't want to go above 90 degrees")?

 

[Sean W.]

increase the voltage at 0.05 at a time.
i wouldnt go higher than 1.25 with the stock cooler.