[...]- about downclocking the memory - mine are at 450MHz, but that's only because at lower MHz sometimes the driver crashes and also it seems to affect the hashing speed. [...]
Hashing with 7970, cgminer + MSI Afterburner I undercloked memory to the amount of 50-100 Mhz with core clock around 1140. I didn't see the impact on hashing power or driver crushes but GPU's fans speed and tempratures.
i have my 6xxx cards memory at 275, i can go lower, below 200, but i do seem to lose hash rate, and higher only affects the temp. I kill ccc, and combine trixx with cgminer and get fan speeds between 1% and 50% with target temp at 70 but usually lower. i must be a lucky one!
Are you sure that MEM is running at that speed? I'm asking because I get report that change was successfully but when I look at MEM speed I see that it is running at 1100. And this happens at every speed below 900 or 1000... Even in afterburner... I can set it but when I look I see 1100 in graphs... Or it could be the driver...