i5 and FSX

Hi,I don't think this has been covered before as a search revealed nothing.I'm an FSX user who's just built an i5 rig. Still getting to know it.I came across Nick_N's thead about tweaking the FSX.cfg file using an i7 and HT.The i5, hasn't got HT. In tast manager, I can't right-click on the fsx.exe process to set the affinity. Would setting the affinity mask to 15 make FSX work on all 4 cores <---is that even possible.Any other tweaks that i5 users are using?On a side note, when I did a clean install of FSX on Win 7 x64, I was getting FPS between 100-200. After install of SP1, that dropped to 20-40 fps before installing 3rd party software. Was there a glitch or have a stumbled across something?I'd appreciate hearing about what other i5 users have done to FSX.Thanks,Stuart Edit: Task manager shows fsx using cores 1, 2 and 3. Core 0 seems to be being used by other stuff. FPS seem doubled when in full screen mode as opposed to windowed mode.