How do you test VRAM overclocking, error-correction?

[Plimogz]

Are there any particularly good apps for isolating the effects of video memory overclocks from core speed? I'm toying with a 6950 and would like to find something that scales well with video memory speed to try and see first hand at what frequency error-correction kicks in and renders any further memory overclock futile, if not damaging.

I've tried running Heaven at a number of core/memory speeds, (between 800 and 880 core / 1150 and 1250 mem) while also running either 4xAF/2xAA or 16xAF/8xAA, and while this method is revealing the expected pattern to some extent, it would be great if somebody can turn me on to a preferred benchmark/app which might be especially sensitive to memory speed.

Oh, and I'm running this at my screen's maximum 1920x1200 res. I figure that the higher the resolution the higher the effect of memory speed should be, but as always I might be wrong or whatnot.

Any remarks on settings or procedures would be much appreciated.

 

[utahraptor]

I hear that this generation of video cards (AMD 7000 / Nvidia 600) use ECC memory so if you push the memory so fast that errors occur it does not crash, but due to all the errors being corrected your memory at 6600 MHz with 1% error rate might go faster than your memory at 6900 MHz with 10% error rate. I am also seeing a guide to figure out the best way to test it.

 

[PowerK]

I hear that this generation of video cards (AMD 7000 / Nvidia 600) use ECC memory so if you push the memory so fast that errors occur it does not crash, but due to all the errors being corrected your memory at 6600 MHz with 1% error rate might go faster than your memory at 6900 MHz with 10% error rate. I am also seeing a guide to figure out the best way to test it.

None of consumer graphic cards this generation uses ECC memory.
Not sure on AMD side, but it's Tesla lines of cards (GTX 690 equivalent and above due end of this year) use ECC GDDR5 memory.