I wouldn't call this a miracle tweak, it might even be placebo! Having struggled a little with my FPS after upgrading recently I went back to the drawing board and completely reinstalled my graphics drivers, FSX cfg and reapplied SP2. The FPS after this was the same as before so I investigated something I read on here known as 'Core Parking' this feature is a Windows setting found with newer Intel processors as a kind of energy management feature where the system will 'Park' cores that aren't being actively used. This relates to FSX because FSX does not utilize 100% of the CPU so you will always likely have some idling during use (I think!). I decided to google around and found this utility which will sort the problem out http://www.coderbag.com/Programming-C/Disable-CPU-Core-Parking-Utility , the utility will test your CPU for the parking flag on each core and allow you to unleash them a little, the results I now have in FSX are tremendous. I can't say that this fixed my FPS or it will do the same for anyone elses, maybe I just hit a sweet spot with my config though it hasn't been heavily modified at all. Anyway I went from having average FPS to a solid 60 FPS at FSDT airports using the Aerosoft Airbus X so hopefully it may be of use to those who aren't aware of it!

 

More Info - http://www.evga.com/forums/tm.aspx?&m=1537904&mpage=1

You can also simply disable core parking by setting the right power options. If you go to the advanced power settings in Windows you can set the minimum and maximum processor power state: make sure both are at 100% and your cores won't park anymore at ALL. Since I don't like to install software if it's not really necessary this is an easier, quicker and cleaner solution. ^_^ There also are regedit 'hacks' that do the same: all not necessary if you can simply do it in Windows itself.

 

I haven't tested if it actually makes a difference on my PC but I always want full power and don't want the CPU to ever slow down, so this setting is one of the first things I change whenever I have reinstalled Windows. (BTW In the same advanced power settings screen you can also prevent your hard disk from taking a nap and disable hibernating (or whatever you call it).