I am on linux, ubuntu server 10.04 to be exact, using catalyst 10.9. I've been able to push a radeon 5830 as far as the bios would allow me, but trying to do so on the 5970 has proven a different problem.
I can set the core clock as far as 800Mhz from the default 725, but anything more and the system just halts. Temps don't seem to ever go above 75C and I'm using the default cooler. I have a 1200W PSU with all the juice in a single 12V rail, so I don't think it's lack of juice.
I've read that the core voltage would need to be tweaked, but I wonder; is that so and, if it is, is there a way to do it on linux? Or should I just get a real cooler instead?