View Full Version : safe voltages for eah6870DC

12-29-2011, 03:40 PM
Hi all, i am curious about the max safe voltage for the eah6870DC. The card comes pre overclocked , so a little bump in voltages is at hand - standard 1.75v - on this model 1.20v.

The most strange thing about the card lies with smart doctor. The software actually allows a voltage tweak up to 1.9v which, considering that all other vendors are allowing 1.35 max, is a little bit scary. So i know what to do for overclocking a video card and all but actually 1.9v can kill the card in my opinion. I have maxed my particular one @ 1020mhz core with 1.3v increase. Actually watching the temperature of the card i can go up to 1.4v but i am not sure if this is going to be safe.
For a desktop processor to have a bump in voltage that high is actually acceptable, but i am not sure about GPUs. So according to asus if i have enough cooling i can go up to 1.9v and not fry my card ?

Do someone can help me here with info. I know that +100-150mv is a normal voltage increase, and many Radeons and Geforces can cope with it with no problems.... but let's say +200-250mv - is it safe when you have the right cooling ? or ?

Many thanks ! :p

12-31-2011, 04:45 AM
Please don't use Smart Doctor, it's old and crappy. >_< I have alerted the team to this.

DON'T USE 1.9V!! TSMC 40nm is not high-K MG, unlike 28nm so it should act more like AMD 45nm CPUs and accept slightly high voltage, however you've got 2+Bn transistors in there so I would not go about 1.35V absolutely unless you're extreme cooling and didn't pay for the card ;) Ultimately you'll have a drop off point where the leakage causes temps to go mental before 1.35V anyway, - that's your safe limit.

12-31-2011, 11:40 AM
The most interesting thing is that even the beta gpu tweak gives me the option to raise the voltage ot that unachievable 1.9v. It's a strange thing to see. Asus makes an advertisement about Voltage Tweaking and gaining 50% more speed with extreme cooling, than gives the normal user the ability to raise the voltage to the sky ....... How do they cover the warranty in that situation. Smart Doctor don't have s special warranty agreement. Other manufacturers are limiting the same card to 1.35v max.

It is very important to give a s safe limit in the upcoming GPU Tweak app. As I sad in the beta I can rise the voltage as in smart doctor. (i will post some more info in the right forum)

Just for the record (if someone cares) my 6870 can top @ 1020mhz core with 1.30v. Actually raising the voltage to 1.40v don't makes any difference, reaching 1040 maybe is possible with that much power but it's pointless. The temperatures are absolutely lovely with the DC cooling. My case is very well ventilated but despite that even at 1.4v and 65% fan speed, the card don't exceed 65 degrees (1.3v results in 60 degrees temps)