At 3.4, 3.6, 3.8 and 4.0 (all on 21 x multi) i was getting a tdp reading of 147.3.
So I guess its just a generic TDP as you would think the current draw would increase as the speed increases ? also it looks like the same reading is displayed no matter what the CPU voltage is (so the answer being the TDP is NOT displayed correctly for an over clockers system !).

Thanks, I noticed it was a question you asked a while back on this forum about the difference between 21 and 20 multi's TDP.
