Hey Andy,Just got FSX up and running with Acceleration, REX (installed, not active) en FEX (installed, not active) and had it running with TrackIR. My system was then using a whopping 3.98GB RAM :( True I run at 1920x1200 with DX10 activated (since I was planning on getting the PMDG JS41), but still...quite a lot.I'm gonna figure out why there's so much RAM used.

How much memory does your graphics card have, I would bet that it is one of the Nvidia cards with more than 1Gb of VRAM, Vista shadows (I think that is the correct term) the VRAM contents in system RAM so this is probably why you are seeing more used in FSX as FSX can use a lot more VRAM than FS9 add-ons tended to do.

no, it's a 8800GT 512MB card. Which reminds me...I need to put it in my signature.

I had the same problem after I installed some heavy scenery until I fixed it today. I am on WinXP SP3FS9.12.99Gb RAM I downloaded and run the "4GB Patch" by Daniel Pistelli which does exactly what is explained above but with a single click. http://www.ntcore.com/4gb_patch.php(Altn.location http://www.softpedia...4GB-Patch.shtml ) Now instead of crushing at 1.95~2.0 Gb I crashed FS9 at 2.4 Gb memory usage. I won't go that high unless I open many browser pages etc. (which I did intentionally on last trial to see how far it can go). Regards

no, it's a 8800GT 512MB card. Which reminds me...I need to put it in my signature.

Also something to look at:Verify that there is no Landclass listing in your Scenery.cfg with a TEXTURE folder. Landclass should have only SCENERY folder, otherwise FS9 will try to read that "blank" texture folder and will use all of your RAM.Pierre