Simple GPU miner with 1x 5850 and 1x 7970.
Pulls 370 watts at the wall with some tweaking of the GPUs.
59C for the 7970 and 68C for the 5850.
850 Mhash/s
P.S. Picture was taken by Potato 2000
One 7970 can do ~700, one 5850 can ~320 easy
I don't like to mess with overclocks, it would get quite hot in the garage, instability issues, temperature issues, and high power consumption.
The higher hash rate vs power consumption isn't worth it. In the end you'll have accelerated electromigration and dead cards.
You can increase GPU speed and reduce Voltage in same line.
When you go to set a Formula1 Race team, you can not start with a Golf R36 and hope to win.
The problem is racing cars have constantly burnt out tires, while graphics cards have electromigration and total errosion of GPU long term