Thanks for clearing that up, I thought thats what you meant.
As far as power, the tower came with a 300 watt power supply but I can't believe it would use that much. Also, as far as ATI cards go, I'm starting to see just how expensive the PSUs are above 750w.

• Is there any way to calculate the usage of the CPU, fan, etc? I know the power usage of the GPUs obviously.
• If I already have this NVIDIA card that runs at 500watt, should I just return it and get an ATI? Is there any doubt it wouldn't be compatible?
• I've been looking at the chart(s) but is there a general rule of thumb regarding model numbers (eg. 7750 vs 6750 vs 5850) when it comes to MH/s per watt?
• I can't seem to find much about what the card identifiers actually mean. I'm wondering if the first number is a _____ then that means it's ______.