Overclocking issues - screen freezing/instability issues

[PvtJkr88]

Good morning Tom's Hardware users.

This is my second attempt at a response for this issue so I'm hoping I can get some answers this time around. Also just to mention I'm pretty new to overclocking so please keep jargon to a minimum.

I have just started to overclock my graphics card after successfully pushing my CPU from 3.4 to 4.4Ghz. All was fine and I managed to find my maximum VRAM and core clock speeds on my Graphics card before I started having issues (Core clock stable until about 1050Mhz and VRAM stable up to 1400Mhz)

Now when I started to try and combine the two and find a safe and stable middle ground so to say, I have had loads of instability and this crazy screen flickering issue where the programs are still running (I could here youtube still playing videos) but my screen looks like a TV with static.
With my settings at 1000Mhz on the clock and VRAM at around 1300Mhz it passes Heaven/Valley/3D Mark and playing Metro Last Light with everything cranked up without a hitch, but I left my computer on over night playing youtube videos and when I woke up the screen was completely glitched.

So I'm really just wanting to know if this is an issue that can be fixed or do I simply just need to lower my clocks and settle for a much lower overclock. My specs are as follows.

Graphics card: AMD HD 7950 Sapphire Vapor X
CPU: i5 3570k
PSU: Corsair 630 watts.
RAM: 2 x 4GB @ 1300Mhz

Any help is appreciated.






*EDIT* Forgot to mention that my tempretures have not exceeded 62 degrees under 100% load even on the higher clock speeds.

 

[bicycle_repair_man]

Overclocking a GPU is very different to overclocking a CPU; the gains are much less.

In my experience, having owned an HD 7850, I found that overclocking the memory would cause crashes, even if it was just a 50Mhz increase. I suspect this could be the same for you. Increasing the voltage may help though.

Overclocking is never an exact science, and particularly with GPUs, you'll find that screen artefacts and crashes will hold it back more than heat.

 

[PvtJkr88]

Ok thanks for replying,

Would you advise me to lower the memory back to the default then and just tweak the clock until I find the best stable result? I'm already 150Mhz above the stock settings so I guess that isn't terrible. I just see so many threads with people that say they have much much higher overclocks than mine. I don't really fancy messing around with the voltage settings until I have looked into it more.

 

[bicycle_repair_man]

Run the same test with the memory overclock enabled and disabled to see when the crash occurs. If the computer crashes only when the overclock is enabled, then put it back to the default speed and just go with core clock.