voltage on a 5850

[bradyapba]

im thinking of upping the voltage on my 5850 to see if I can push the OC a little more. Anyone know what the acceptable upper range for the voltage on the 5850's are?

I dont want to try it, without a little knowledge of where the upper limit is.

Thanks!

 

[MrK6]

Up to 1.3V on the core is perfectly fine. As with all overclocking, make sure you keep an eye on all your temps, especially that of the voltage regulators. You can use GPU-Z to monitor everything.

 

[bradyapba]

thanks! Yes, i keep and eye on both. after a few hours of testing,

im up to 795/1170 on stock voltage, fan set to 40%. (the loudest im willling to let it run at)

it passed ati gpu tool stability test for an hour, no artifacts. Temps maxed out at 53 for GPU, and 52 for the memory.

I gamed on it for 5 hours straight, no issues, temps maxed at 46/45 for GPU and Memory.

Im hoping to get more out of it, as heat is not an issue, temps are real good, so it would seem i could increase the volts and be ok.

 

[MrK6]

With these 58xx chips I've found that an overclock's stability is directly dependent on operating temperature - the colder you are, the higher you'll go, and voltage doesn't come into much play until you really start to crank the chip. That said, you have to find settings where the fan gives enough cooling but doesn't drive you nuts, and you can give it as little extra voltage as possible but still get a very high overclock. Good luck!

 

[bradyapba]

i get artifacts at anything over 805/1180, and its not heat, because just to test, I turned the fan up to 75%, and it keeps the temps in the 45/45 range, but still get artifacts.

I also have 2 S-flex 1600 fans, modded into my case windows, right over the front and back of my VC, so its getting a lot of cool outside air, which I know is helping.

So with those temps, i think its pretty safe to assume, its not heat related.

So either im at the max of what my card can go, or it wants some more volts. We shall see.

I also have a arctic cooling twin turbo pro coming tomorrow

 

[MrK6]

Exactly, now you need more volts. But only raise it a little bit (~0.025 at most) and try going higher again. The voltage increase will go a long way as long as you keep the temps low .

 

[MarcVenice]

Crank it as high as you want, OCP will protect the gpu anyways Won't be good for thermals though.

On a more serious note, with aftermarket cooling, you can do 1,3v and if the gpu is capable, reach 1000-1025MHz.

 

[Tempered81]

only raise it a little bit (~0.025 at most) and try going higher again. The voltage increase will go a long way

Solid advice there. Use MSI afterburner for voltage, core, memory, & fan changes. ASUS or MSI bios will give you higher CCC limits for core & memory.

 

[bradyapba]

Yes, im use afterburner, because I have the Arock board. Works great.

using ati gpu tool for stability check. Using furmark for scores to check for throtlling.

Im not new to oc'ing, but never messed with voltage on a VC before. So thanks for the advice, I will be careful.

 

[MarcVenice]

Yes, im use afterburner, because I have the Arock board. Works great.

using ati gpu tool for stability check. Using furmark for scores to check for throtlling.

Im not new to oc'ing, but never messed with voltage on a VC before. So thanks for the advice, I will be careful.

Like I said, you CAN'T kill the gpu by overvolting. The chip can withstand 1,8V (I ran several HD 5870's at 1,8V), the thing is, when there's to many AMPS going through the gpu, OCP (over current protection) will kick in, and shut down the card/throttle it. So don't worry about killing it with to many volts.

To much heat could kill it, or lessen it's lifespan, but only if you blow past 85 degrees Celsius. You do seem to know what you're doing though, coz you do have to watch the scores, as this picture will demonstrate:

As you can see, more voltage, at the same clockspeeds, decreases performance. This was with a HD 4890, but the same holds true for any 5000-series card.

 

[bradyapba]

Yup thats how I assumed it worked, and i was watching for it. Good to know about the volts.

Yeah, my temps never break mid 50's, so im nowhere close to 85C, and im only running the fan at 43%. And I have the TTP coming tomorrow, combined with the outside air blasting it, temps are not gonna be an issue. Im pretty sure I can push the card to its limit, and temps wont be an issue, im never even going to come close to 70C. Im pretty sure I will be able to find the max this card can do, im going to get artifacts because i reached the limit the card can do, or throttled due to the protection. Heats not gonna be my issue.

I just wasn't sure I clearly understood how the increasing the volts would affect the card. I wanted to make sure I knew what I was doing. I think i have a pretty clear idea of whats going on now, and how the card works. I really appreciate you guys talking me through it.

 

[bradyapba]

Ok it sure does like volts, up to 1.18 volts, and thaty allowed my OC to go to 850/1170. I have not pushed it further becuase temps have gone to 62C on the GPU and 70C on the memory. Thats about where the edge of my comfortable temp zone is

But i still need to put on the cooler

But i do have a question, wheen you guys run the stabilty test in GPU tool, how long do you let it run, without errors before your satisifed its stable? I let it run for 10 minutes just as a test.

Thanks!