Safe GPU Core Voltage

[azrul]

Hi,

I just bought a new Sapphire 6870 and I was a bit disappointed on the overclocking abilities compared to my 6790. Right now, the max frequency that I can squeeze out of the gpu is only 960MHz which is not really much since the default core settings was 900MHz.

So, I'm thinking that I would like to increase the voltage a bit but not really sure how to do it safely.. What is the safe voltage for a GPU such as this HD 6870? Is the procedure the same as how we do while testing the GPU and RAM frequency? Means, increase the voltage one level at time.

 

[HostileDonut]

Well, there isn't really a "safe" voltage for most graphics cards. 60Mhz out of a hd6870 on stock voltage is pretty good as that card is not known for its overclocking. Some people say just go until it gets too hot, but that he GPU can take it, but I wouldn't go past .1v past stock. I like to keep it around .05v from stock, but .1 probably wouldn't hurt if you have good temps. Just make sure there isn't any artifacting. Watch it carefully for a little while and check temps.

 

[Eviscerare]

Don't quote me on this but I doubt you'll ever 'burn out' a graphics card even if you crank it up to max voltage these days. If you just Google 'max overclock [insert your card]' many tech sites will have already achieved a max overclock in which they used max or close to max voltage. I reason that your system will probably kill the video driver or just crash entirely first, warning you of an over voltage issue before the card actually dies on you.

I personally have a nvidia MSI GTX 460 Hawk Edition and I cranked the voltage up to +100/+100/+30 using MSI Afterburner, and it's been almost half a year now running fine.

 

[HostileDonut]

Don't quote me on this but I doubt you'll ever 'burn out' a graphics card even if you crank it up to max voltage these days. If you just Google 'max overclock [insert your card]' many tech sites will have already achieved a max overclock in which they used max or close to max voltage. I reason that your system will probably kill the video driver or just crash entirely first, warning you of an over voltage issue before the card actually dies on you.

I personally have a nvidia MSI GTX 460 Hawk Edition and I cranked the voltage up to +100/+100/+30 using MSI Afterburner, and it's been almost half a year now running fine.

Yes, but running a high voltage through a card may not fry it, but can degrade the life. That is why you should keep the voltage as low as possible.

 

[azrul]

Yes, but running a high voltage through a card may not fry it, but can degrade the life. That is why you should keep the voltage as low as possible.

I found few sites also mentioned that they had increased the voltage up to 1.2v out of 1.175v stock voltage and seems they manage to clock it up to 1000Mhz GPU/1200Mhz RAM. That is the same clock that I manage to get out of my old HD6790 without any voltage increase. hm.. I think I miss her lol.

So, after 1 night finding a stable clock. I settled down at 965Mhz/1140Mhz no volt increase and it does handle games well though. I'm running battlefield 3 (all out) at 50fps average which is nice for the eyes already. Only that I just cant stop thinking bout cranking up a little bit considering the price is almost twice the price for 6790.

Will have a try again with .05v - .1v increase tonight and see any improvements that I can get. Ill come back with the result. Thanks guys

 

[HostileDonut]

No problem!

 

[azrul]

I think I had found the ultimate stability for my gpu now. 985Mhz/1180Mhz but at a voltage increase of 0.03V.. Can that voltage be sustained just for daily use as well or I should only just use that clock when gaming? I read articles before saying that frequently changing the clock settings could damage the card overtime. Is it true?

 

[HostileDonut]

I think I had found the ultimate stability for my gpu now. 985Mhz/1180Mhz but at a voltage increase of 0.03V.. Can that voltage be sustained just for daily use as well or I should only just use that clock when gaming? I read articles before saying that frequently changing the clock settings could damage the card overtime. Is it true?

What your video card has on it are settings such as idle, where the card may run at low voltage and only 50Mhz, or something very low, a media setting for movies and such where it runs maybe 500Mhz or something, and a game setting where it pumps it up to you 985Mhz. So, the card will idle at lower speeds. No, it will do no damage by overclocking the card with a modest voltage and a modest clock.

My GTX 460 1gb stock clocks are 675/1800/1350, but then I overclocked it to 875/2050/1750. Right now the clocks are running at these though: 50/135/101

So as you can see, the clocks reduce when not needed, not doing any damage.

 

[azrul]

Ok .. Btw, let say if I'm already happy with what Im getting on the GPU freq, but then the memory seems not tolerating anymore increase at this voltage. So if I increase it the volt a little bit more would it help? Cause from how I see it, the name is CORE voltage and sounds related only to the GPU but not the RAM. is it?

 

[HostileDonut]

Ok .. Btw, let say if I'm already happy with what Im getting on the GPU freq, but then the memory seems not tolerating anymore increase at this voltage. So if I increase it the volt a little bit more would it help? Cause from how I see it, the name is CORE voltage and sounds related only to the GPU but not the RAM. is it?

Yes, the voltage is related to the shaders and cores. I think that is it works.

 

[azrul]

yes seems it does, but I cannot manage to have a stable clock. Some games would just hang. Never mind, I think I can manage to work through from there. Thanks for the advice, it was really helpful for a newbie like me.

Just one more small thing, it seems whether on idle or not, reading on GPUZ still shows voltage is 2.105V, may I know how do you get your readings? Or is it my ati just doesn't work like your nvidia?

 

[HostileDonut]

yes seems it does, but I cannot manage to have a stable clock. Some games would just hang. Never mind, I think I can manage to work through from there. Thanks for the advice, it was really helpful for a newbie like me.

Just one more small thing, it seems whether on idle or not, reading on GPUZ still shows voltage is 2.105V, may I know how do you get your readings? Or is it my ati just doesn't work like your nvidia?

The voltage should go down on both Nvidia and AMD cards. Use CPU-Z and GPU-Z to check readings. If it doesn't lower the clocks and voltages, then you may want to down the overclock until it does. Do you have a setting on that is forcing an OC or any other programs running? I would turn off all other programs and see what happens.

 

[azrul]

I think it trixx that causing it. Well at first i thought even though the card is on OC'd state, the voltage will still automatically reduced as well. So i guess I will have to turn it of and restore the OC only when needed. Thx

 

[HostileDonut]

No problem!

 

[Guest]

Most of the card manufacturers wont give you more than the card can handle anyway.