ok, now your here, it implies three things: 1. you have more money than me because... 2. you have a dual core cpu and relatively up-to-date pc and finally three, 3. you have FSX Ok, now thats out of the way lets get to why you're reading this. You may (or may not as the case may be) have noticed my post in the FSX Tweaks sticky, but i've been looking into this - low FPS in FSX - a lot more of recent, especially the possible causes of slow(er) performance with Dual Core CPUs such as Intels' awesome Core 2 Duo and AMD's not so great counterpart the Athlon X2. I've found some very interesting articles and information on the web that could be of benefit to you all, so listen in!! Firstly, are you sure that your CPU is really giving you every ounce of juice it has? Check out your Processor Affinity. This determines how many cores of the CPU FSX is allowed to utilise - as a default it appears that its only enabled on one core. So, how to do it, simple, here's how!: with FSX running, do a 'CTRL+ALT+DEL' > select 'Processes' > right click the FSX process > choose 'Set Affinity' when you've done the above you'll see this (image courtesy of Toms Hardware Guide) When you've got the Affinity window showing (again, image from THG) simply select which cores (both, obviously) you want FSX to utilise. note: you'll need to set these everytime FSX starts, there are however utilities to do it automatically, just Google it!! Secondly, the above steps may not actually be fully affective. The reason, a Dual-Core hotfix for XP SP2 from Microsoft. Do you have it installed, if not, or aren't sure then you can get it here, and information about it, from here You'll need to install the hotfix manually however, this is done as follows NOTE: This requires editing the registry - MAKE A BACKUP FIRST!!: Go to Start, Run. Type regedit and push OK. Navigate to HKEY_LOCAL_MACHINESYSTEM/CurrentControlSet/Control/Session Manager. Right-click Session Manager and do 'New', 'Key'. Type Throttle for the name. Right-click 'New', 'DWORD Value'. Type PerfEnablePackageIdle for the name. Right-click PerfEnablePackageIdle and click 'Modify'. In the 'Value' data box, enter '1' (without quotes, default is most likely '0'); make sure Hexadecimal is selected and push OK. Close the registry editor. Thirdly, download and read this very detailed and informative PDF datasheet, it details everything you'd ever need to know about tweaking FSX for raw performance with a balance of quality - check it out!! Well, thats all from me, hope you find this useful. Of course if youre willing, or daring enough, to try the above suggestions, please do post your experiences here as im sure we'll all be happy to hear of some real word information as to if they work or not!