I did the various FSX and nhancer tweaks from http://www.simforums.com/forums/forum_posts.asp?TID=29041 (and the 855 tweak as well), yet still FSX feels somewhat choppy on approach when using two monitors at 1280x768. Single monitor it seems ok.Here's what I have:MSI Platinum Intel i7 820 OC'd to 2.96 ghz6 gigs 1066 at 7-7-7GTX 260, 896 meg RAMWin XP 32 bit500 gig WD SATAseveral GoFlight modules and throttle quadrantI run Alacrity before I start up FSX. AVG virus scanner stays running.

What do you mean by "855 tweak"?You have to follow Nick's guide to the letter. Not a tweak from here and there.

What do you mean by "855 tweak"?You have to follow Nick's guide to the letter. Not a tweak from here and there.

If I recall AffinityMask.

Than you probably mean 85 with HT on. Try using 14 with HT off. It works for me.

I did the various FSX and nhancer tweaks from http://www.simforums.com/forums/forum_posts.asp?TID=29041 (and the 855 tweak as well), yet still FSX feels somewhat choppy on approach when using two monitors at 1280x768. Single monitor it seems ok.Here's what I have:MSI Platinum Intel i7 820 OC'd to 2.96 ghz6 gigs 1066 at 7-7-7GTX 260, 896 meg RAMWin XP 32 bit500 gig WD SATAseveral GoFlight modules and throttle quadrantI run Alacrity before I start up FSX. AVG virus scanner stays running.

Cpu 820 or 920???Try a lower resolution for your monitors.No offense to the author of Alacrity, but I find for my computer it does nothing.You can try 'hyperthreading' on and off and see if it makes a difference?Set affinitymask to 15 = four cores.[JOBSCHEDULER]AffinityMask=3use these settings for N as you test and you must EXIT the sim and relaunch between changes255 - all 8 in use254 - 7 in use with the first remaining free252 - 6 in use with the first entire CORE remaining free127 - 7 in use with the last remaining free 63 - 6 in use with the last entire CORE remaining free 1 = 1 core 0001 3 = 2 cores 0011 7 = 3 cores 011112 = 2 cores last 110014 = 3 cores last 111015 = 4 cores 1111You have 6GB of system ram and Windows XP 32bit can not make use of it for FSX.Have you checked into the '/3GB /userva=2560' parameters for the 'boot.ini' file? Which would allow the use of 4GB.