First of all the E4300 stock speed is 1.8Ghz which means you overclocked. Yes I didn't notice the CPU Mhz but just assumed that you would use stock speeds when testing.
If you are really that certain that Wine is not the problem, why are you so reluctant to prove your claim with running native vs native.
Also the numbers on the linux drivers doesn't really translate directly to Windows numbers AFAIK.
Btw. check this link :
Another thing. Could you test wether your overclocked CPU is REALLY running at that speed? I've seen some posts somewhere else that overclocked CPU's might get reported wrongly. For instance what is the CPU speed score in 3dmark03?