GPU Memory Overclocking Question

[earwicker7]

Now that I've got my CPU overclock nice and stable, I'm doing my GPUs; I have two HD7970s.

I'm using OCCT, with a max framerate of 120FPS, and for the core speed, assuming it didn't crash or give errors, I just checked the graphs and made sure there weren't any FPS dips; whenever there was, I'd just up the voltage until I got a flat line for 30 minutes.

Is there anything in particular to look for when doing the memory overclock other than crashes or errors? Will the FPS be bottlenecked from the start because of the low core speed (it will be at stock now that I'm adjusting the memory)?

 

[PP Mguire]

VRAM handles how quickly textures and info is fed to the GPU. In that case, what you look for isn't FPS but rather artifacting on the textures, color blinking, and wild texture tearing. When you start getting these you are pretty much at your limit. I've noticed that on cards with higher VRAM capacities adjusting the speed doesn't have that much of an impact as upping the GPU clocks. Unlike for me with only 1.5GB, on games that tax the crap out of VRAM (like my modified Skyrim) upping the VRAM clocks helps greatly.

Just a heads up, OCCT, Intelburntest, and Furmark are known hardware killers. They stress the hardware more than regular programs would.

 

[earwicker7]

I know Furmark has a bad reputation, but I've used it safely in the past... I'm very slow at overclocking, and I don't push things farther than they should go. This is my first time using OCCT and this methodology, though... in the past, I used Furmark and just looked for artifacts; I'd never noticed the unstable FPS issues, since MSI on its own gives you a real-time graph, but not one you can look at after the fact.

Thanks for the answer... I'll just keep an eye on the screen while the tests are running.

 

[PP Mguire]

Those 3 specifically all do. You can burn up even stock hardware, so just be careful with long test runs.

When I'm looking for max GPU clocks I typically use Kombustor or do lots of 3dmark 11 benching on X level. It also helps to Google for people with your specific card to get a feel for how high they can usually get.