The core's problem is voltage, at least in my case. My card tops out at about 78C or so in 3DMark05 (oddly FEAR raises it to 85C
). The freezing I get is characteristic of the GPU crapping out because of lack of power. However, I agree whole heartedly on the RAM. Some really nice low profile heatsinks would be ideal. Unfortunately, the bottom RAM chips are too close to the mobo to have anything but a plate on them (unless you do a custom design, I guess) and the ones under the top heatsink are blocked from any airflow, so major hacking would be in order if one wanted to better cool the card. I dunno, it's a tough one
EDIT: oh yah, ATiTool is rock stable up to 435 core for me. 450 artifacts isntantly. However, it would make sense that you can do it stably because you got your core up to 500 and mine craps out at 480.