Well bro i'm currently running the system on cm460 watts so not pushing the GPU to the limits^whats the max u achieved with ur HIS 4870??
I'll be getting the Corsair CX400 tommorow so will c what this baby is capable of, it's kinda already factory clocked at 770 on the core and 4ghz on the memory (gddr5).
On stock i have a bandwidth of 128 gbps as compared to the reference 4870.
On ocing, it at ran stable with Furmark at about 149.8 gbps (1162mhz memory clock) and the funny part is dat the temperature didn't pass 59 C on 100% load. And while playing crysis the change was noticable the FPS didn't go below 40 at everything at very high but no AA. I'll update the performance on i get a good PSU as i don't wanna risk anything