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AMD 7950 Overclocking

Oberon

Oberon

Oberon

Associate
Joined
27 Jul 2004
Posts
544
Location
Milton Keynes
Afternoon gents,

I recently purchased the HIS HD 7950 from OcUK and it's a cracking card I must say. However having seen the performance of the GTX 670 and becoming all green eyed I've decided that it's a lazy card and it needs some motivation.

I got on to some guides about OC'ing it and they all report of getting speeds of 1.1Ghz core and 1.5Ghz mem without even touching the voltage (+20% power though). I got to 1Ghz core easily, no problems there. But the memory is causing problems around 1.4Ghz. I'm getting Artifacts, driver crashes and lockups etc. I did have problems through Overdrive in the AMD CCC utility, so I'm using afterburner now.

Question is, what stable clocks did you manage to achieve without touching the voltage? Looks like if I want to get to the speeds reported in some of the reviews, I'm going to need to bump it up, but I cannot seem to find the safe voltage range. If someone could point me in the right direction that would be great.

Thanks for reading :)
 
My temps are 65-70c. The problem is now that I've realised the drivers are crashing when I get the supposed hangs/stalls, which leads me to believe it is just the drivers. Wonder if anyone else had this problem?
 
Oberon said:
Afternoon gents,

I recently purchased the HIS HD 7950 from OcUK and it's a cracking card I must say. However having seen the performance of the GTX 670 and becoming all green eyed I've decided that it's a lazy card and it needs some motivation.

I got on to some guides about OC'ing it and they all report of getting speeds of 1.1Ghz core and 1.5Ghz mem without even touching the voltage (+20% power though). I got to 1Ghz core easily, no problems there. But the memory is causing problems around 1.4Ghz. I'm getting Artifacts, driver crashes and lockups etc. I did have problems through Overdrive in the AMD CCC utility, so I'm using afterburner now.

Question is, what stable clocks did you manage to achieve without touching the voltage? Looks like if I want to get to the speeds reported in some of the reviews, I'm going to need to bump it up, but I cannot seem to find the safe voltage range. If someone could point me in the right direction that would be great.

Thanks for reading :)
Click to expand...

Without touching the voltage, probably around the same as you said in this post using the Sapphire 7950 OC edition which is normal (stock is 900MHz as opposed to your 800MHz). I can get to 1200MHz clock and 1500MHz memory with about 1250-1270 voltage using Trixx (default is about 1050-1080). Funnily enough I always forget to check the load temperature but I get idle temperatures of 32-34 degrees with this. Completely default I am at 29-31 and both are on 50% fan speed or less which is excellent.
 
I know this is an old thread but as ive started to tinker with my new HIS 7950 I came across this, on stock voltage, but with +20% power I can get 1200 easy, but the memory starts to cause me problems, highest I've gotten it to go and pass a benchmark was 1480, it got through 3d mark 11, and higher and it crashes with a blank screen etc, however 30min-45 mins of diablo 3 (not a very intensive game) causes a crash so it wasnt as stable as I thought, pretty sure its the memory, might have to tweak the voltage if I want the memory clock to be stable/to gain a bigger result.
 
Doco said:
I know this is an old thread but as ive started to tinker with my new HIS 7950 I came across this, on stock voltage, but with +20% power I can get 1200 easy, but the memory starts to cause me problems, highest I've gotten it to go and pass a benchmark was 1480, it got through 3d mark 11, and higher and it crashes with a blank screen etc, however 30min-45 mins of diablo 3 (not a very intensive game) causes a crash so it wasnt as stable as I thought, pretty sure its the memory, might have to tweak the voltage if I want the memory clock to be stable/to gain a bigger result.
Click to expand...

Memory clocked too high generally brings along artifacts over the screen and the GPU core clocked too high will crash the game/screen/computer.
 
Good to know, I'l get more precise O.C. tomorrow after work, but when doing it today - anytime I upped the memory to 1500 (or above 1480 really) the screen would go blank and I'd have to do a reset, I assumed it was the memory because I didnt encounter the problem atal when i touched the gpu core, but then again I only overclocked the memory with the gpu core at 1200, Ill keep it at stock and only move the memory tomorrow - see where my wall is, thanks for the info :)
 
Doco said:
Good to know, I'l get more precise O.C. tomorrow after work, but when doing it today - anytime I upped the memory to 1500 (or above 1480 really) the screen would go blank and I'd have to do a reset, I assumed it was the memory because I didnt encounter the problem atal when i touched the gpu core, but then again I only overclocked the memory with the gpu core at 1200, Ill keep it at stock and only move the memory tomorrow - see where my wall is, thanks for the info :)
Click to expand...

No probs and good luck :)
 
chipachap said:
Would that not suggest it was a core problem though??
Click to expand...


I don't know, he didn't say what type of artifacts he got. Core artifacts are like white dots on the screen on these cards. Memory artifacts are missing textures, big triangles etc that are really obvious.

What I'm saying though is at the same core speed, your memory can over clock a little higher as you increase core voltage in my experience.
 
Kept core clock at stock settings, moving up mem. clock and it wont budge past 1480, either my pc freezes when loading 3d11 or my screen goes blank during a benchtest, would increasing the volts a bit (not too much, dont want to shorten the l.s completely) help make a stable overclock, and would you recommend it?
 
Doco said:
Kept core clock at stock settings, moving up mem. clock and it wont budge past 1480, either my pc freezes when loading 3d11 or my screen goes blank during a benchtest, would increasing the volts a bit (not too much, dont want to shorten the l.s completely) help make a stable overclock, and would you recommend it?
Click to expand...

Yes I would. Reports of reducing lifespan etc are greatly exaggerated, just scaremongering really. The card wlll be replaced for being too slow long before degradadion supposedly kicks in. As long as you are sensible, a little voltage increase is fine. Try 1.2v or 1.225v and test it.
 
I think I've hit my wall. I can move the VDDC to 1250 mV and MVDDC to 1680 mV and cant get past the 1480 barrier at all (this is also with +20% power and no other overclocks) my screen will just go blank (sometimes at the start of the testing, other times part way through) and I have to reset the pc, not everything can be overclocked to max settings, but I'm happy enough with a 1200 core clock and 1450 mem. clock (just to be on the safe side lol). On a side note I know its not a heating issue, ive only seen my temperature go over 60 degrees once, after a 1-2 hour gaming session, have to say the cooling on the HIS card is impressive (well could be on all the cards but I've only my card for reference lol)
 
I had the same "problem" with my VTX3D HD7950 X-edition.
The core clocked really well 1100-1150 mhz, no problem.
But the memory was shaky even at 1450 mhz ( I got artifacts in BF3), so in the end I had to settle at 1425 mhz for the memory.
 
I thought with GDDR5 round off checking you wouldn't get artifacts from unstable memory, instead the memory would repeat the process until it was successful giving a decrease in performance.
Or maybe I'm just spouting out my rear end again...
 
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