Confusing Issue Overclocking XFX HD7770

[SublimeOrange]

Hi there,

My previous posts were all about me trying to find the solution to my computer periodically freezing, after much hassle and troubleshooting, it appears to be the clock speeds of my Crossfired XFX HD7770s.
I have 2 similar XFX models, both DD Cooling, but only the first card is a Black Edition Factory Overclocked. I bought the second card a few months later thinking I could just bump up the clock speeds to the same as the first card, as it wouldnt have any heat issues because its essentially the same design, but it appears the second card doesn't like being at the same (higher) clock speed of the second card and is causing issues.
Any ideas as to why this might be? Does XFX increase the voltage slightly to get higher speeds that other Graphic manufacturers, meaning the second card would be unstable without those higher voltages?

The overclock was from 1000/1125, to 1120/1300 (The same as the first "factory overclocked" card).

Many thanks

-SublimeOrange

 

[Robert Pankiw]

If you're OCing your card, you need to check for stability. The manufacturer may not have factory OCed that card because they knew it couldn't handle the speeds (or maybe it could, and they needed a card to fill a certain market segment).

I'll assuming having the faster card operate at the lower clock speed (which is handled automatically by the drivers, no work needed) is not an option you want to consider *though may be smart, it's what I'd do*.

Look online for OC guides, there are hundreds. It usually amounts to slowly, carefully, and painstakingly incrementing voltages by the smallest amount and stress testing at each point. That's the only sure way to get the lowest voltage for a given clock cycle.

 

[SublimeOrange]

The thing is, I've already stress tested using Furmark and I have no problems. My computer only freezed every so often in a day, maybe every 2 or 3 hours..?

 

[Robert Pankiw]

It only freezes in the crossfire setup but not when used alone?

It's recommended to leave a stress test run for 24 hours to determine if your system is stable. I'll assume you've done just that.

Does the problem exist if you use the stock settings while in crossfire? If it does, you may have a bigger problem. If it doesn't, then it's your OC. Also, I have no idea what XFX does to their cards to hit their factory overclocks. Also, by issues, do you mean the freezing which happens every 2-3 hours, or do you mean higher than normal temps?

Sorry if I'm not being much help.

 

[SublimeOrange]

Using stock settings while in crossfire works fine, as I have tested.
I usually only run Furmark through the 15 minute setting.
Earlier I was looking at some numbers on GPU-Z while furmark was running and it appears even at the same stock clock speeds, the first "factory overclocked" card has a high voltage than the second card, 1.2v to 0.825v, and I believe this is probably the reason behind the second card not being stable at the same clocks as the first, on a lower voltage.
Is there anyway I can increase the voltage on the second card? I've tried in Afterburner and ticked the boxes need, restarted etc, but I am still unable to move the voltage slider and was wondering if there is another way to increase the voltage other than Afterburner, or is the voltage "locked"?

 

[Robert Pankiw]

Legit Reviews overclocked the XFX Radeon HD 7770s too, but ran into the same problem as you. The stock 7770 doesn't reach the settings the factory overclocked 7770 can reach.

As far as I remember, you can adjust the "Power Control Settings" (pictured on their site) but not the voltage directly. Of course, I don't have a 7000 series GPU, so I don't know first hand.

15 minutes is not long enough to determine stability. 0.825V seems like an idle voltage to me. Oh poop brigades, I thought I pressed send on this.. I wrote all this over an hour ago.

Uh, if Furmark reports higher scores in crossfire than in single GPU mode, then it likely isn't idling.

P.S. I'm sorry I'm super slow at replying, I haven't been on Toms as much as I used to. I hope someone else that actually knows more than me shows up! 😛