Overclock 6990 in Ubuntu, Same Config but Diff GPU Load?

[stick_theman]

I have two 6990s in my box, so there are 4 GPUs in total.

My question is, how come my GPU1 load is at 99%, while my GPU2, 3, 4 load are at 61%, 60%, 40% respectively?

They are all overclocked the same way.

code: DISPLAY=:0 aticonfig --od-setclocks=900,1260 --adapter=all