280x: System Draws Less Than 300W Max

I have run some benchmarks, and my kill-o-watt is telling me that the system doesn't even draw 300W from the wall while gaming/ running gaming benchmarks. When I put together this rig, I was trying to keep heat output/power use as low as possible, so I guess that might have something to do with it, but it still seems odd to me.


My rig:

CPU: i5-4430 84W @ 3GHz

GPU: XFX DD 280x OCed @ 1150 mHz core 1600 mHz memory

Ram: 8GB Kingston 1.5V @ 1600 mHz

System drive: Sasmung Evo 250 GB

Storage drives: ~7TB of assorted drives (three hdds total)

PSU: Seasonic 650W Gold rated

Fans: 5 case fans (three from the Arc Mini R1 and two pulled from a Rosewill Blackhawk that was in a previous build)


looks normal to me ☺

This is about what I see with my HD 7950 and i5 3570k @ 4.0 Ghz. I only have an 80+ Brozen Corsair though.

Really? Because every time that I look into it, people are saying that there is no way that you should be able to crossfire a 280x (7970) with less than a 750W psu. According to my numbers, I ought to be fine with my 650W and still have plenty of room left over, even with my OC.