Vista + fsx + sp1, system defrag, no antivirus, no antyspyware, all services/processes non necessary stopped, directX updated june 2007, tried several catalyst driver (at the moment I have the latest, 7.6) with all possible settings combination (AA, AF, etc), tried CFF Explorer solution for OMM on Vista, etc, etc, etc.With a fsx+sp1 clean installation (no fsuipc or any other addon),after a 2 or more hours flight with default learjet (VC or 2D, no difference), before I begin the descent I have fluid 40-50 fps. When I am at about 5000 feet (over any zone/airport in the globe) I have 3-5 fps with heavy stutters (fsx freeze for 2,3, even 10 seconds). If I pause the simulator the magic is back: very fluid 30-40 fps (this should exclude a memory leak problem: it wouldn't make any sense to have no memory problem with the sim paused, and the 3-5 fps + stutters when I press again the P key).I suppose it is something related to the graphic card. Any advice? Do you think I should buy a new VGA? Or give up?Thank you.IgorIntel core 2 Duo e6400ABIT MB AB9SAPPHIRE X1900GT 256MB2X1GB DDR2 Corsair PC5400Hard Disk Hitachi 250GB S-ATA2

Just a quick thought - have you tried a descent with zero weather? As you descend you move through a variety of cloud layers and FSX gets busy redrawing new layers etc. It might be worthwhile checking if this is the problem - the pause might be providing time for FSX to load and redraw etc.Andrew

I tried with clear weather, overcast, ecc. No difference...Thank you anyway.Igor.

It looks like you have the Out of Memory (OOM) bug. There's a fix (http://www.nvnews.net/vbulletin/showthread.php?t=89138). You might do a search in this forum for "Out of Memory" or "OOM". Fellow simmers, including me, who have had this problem had it fixed by applying this fix even with just 2 gigs of memory. Also make sure you have installed the microcode fix for your chipset (http://support.microsoft.com/?kbid=936357).Best regards,Jim

As I wrote in my post, I tried that OOM fix with no result. About the microcode, I'm going to install it tonight.Thank you.Igor

Hi, what's your global texture quality slider at? If maxed, reduce it a notch and try again. A 256MB GPU is not enough for FSX with 1024x textures & elevated settings. Hope this adds to thoughts Jaap

Are you running autogen? Big hits when you're at about the altitude you indicate.

But after hitting pause and then resuming the program, his frames go back up! So it can't be autogen.

No autogen... anyway, it would be very strange autogen could hang the sim for five or ten seconds. I think it is a graphic issue, maybe a VGA memory problem, but I'm not sure.Igor

I agree with Igor, this really sounds like a driver issue. Vista drivers have not caught up with the OS. Both nVidia and AMD/ATI are having issues. Until a decent set of drivers is released, we're going to suffer with these kinds of problems.Every system is different and some don't experience any problems in Vista. But they're few and far between. As drivers mature, these annoyances will hopefully diminish.Regards,Jim Karn

Do you think I could solve my problem switching from my ati x1900 GT to Twintech Geforce 8800 Gts Xt 320mb or similar? It is just an idea ...Igor