fsx / 9.1 and a new computer

So I waited for the new fsx to come out and I broke down and bought a new computerIt is pretty well as decked out as possible with Ati 1900 xt video, great sound, two raptor drives and 4 gb of memory. Dual core and xp-proI decided to do nothing with this machine other than use it for fs in order to see what is possible in terms of performance.I use lots of add-ons in 9.1 including widefs and fsuipc to run a number of app's. I mostly fly online so that means limited AI. I must say that my fs9 install is amazing , no stutters and great frame rates. Note that I run everything in the fs settings at full tilt. I then loaded up fsx , no add ons, same computer, I did load fsuipc and 4.02 and fsinn? . I am running widefs and avs 6.5 on the second machine.I tried to try to ramp up the settings to max in fsx, in order to see how well this would run. I set the frame rate target around 15. The result was that when I ran the stock 737 in this configuaration, the frame rates were terrible and sluggish. I had an incredible amount of stuttering , This really shocked me.I am not sure why I would use fsx. Perhaps there will be a good reason once vista is out but at the moment I think ill stick with fs9 for a great flying and realistic experience.Anyone else had this same result?Peter