Hi,I have not seen a thread related to this problem before, so pardon me if I repeat something that's already talked about. I am running FS9 on a dual monitor testbed for my Lear 45 simpit construction project. I'm running with 4 GO-FLIGHT modules (although the throttle quad has to be sent back due to a squirrely USB connector). However, I note that as I run the sim, flying any plane, with dual screen or not...as time passes, my frame rates decrease. I'm running a pc I built for this application, with the following:Asus A8NSLI32-Deluxe mobo2 GB OCZ Titanium RamAthlon 64 FX-60 Dual Core cpu2 eVGA 7600GT graphics cards, 1 per monitor at the momentCreative XFi Fitaly ExtremeGamer Sound card2 500GB SATA 3.0 Seagate HDsand the usual other kit to complete the box.Starting out with standard scenery +/- Active Sky 6.5 graphics (seems to make no difference), I get about 60 FPS (locked at 78 for now, but I have tried unlimited too). Tweaked the FS9.cfg file as best I can after reading the posts....the sim is glassy smooth at 80 fpi, but over time, even if I let the sim just fly itself for a while, the frame rates decrease to the point where they stabalize at about 6-9 fps...and stay there despite restarting FS. Only a reboot of the computer will get the frame rates restored to normal, only to decay over time again. I'm trying to quantify how long it takes to decay, but I wondered if this is a known issue and how to resolve it.Thanks for any help!!!!Mark

Mark- Yes, I see something similar, although nowhere as drastic- perhaps a 10-30% slow decline in FPS. I have the FS9 command "Refresh Scenery" mapped to a spare keyboard key (Pause/Break). Just hit this & FS pauses for 2-4 seconds then restores best FPS and you carry on with the flight. Quite useful- especially in prep for landing.System is an ancient AMD XP2200 1.8 GHz with triple GeForceFX5200 cards running triple views LFwd,Fwd,RFwd on 3 mons. UT, PMDG 737/747, ATR72, DreamFleet Baron 58 add/ons. Frame rate NOWHERE near yours but steady and very comfortable. Hope this helps. Alex Reid CYYJ

It might be a scenery issue but it might also be ActiveSky. I no longer use any online weather programs on my mighty DELL XPS set-up because I found this interfered with PC performance and sim fluidity.That said, it could be almost anything else including AV, an auto disk defragmentation in the background, and so on.One other thing: it could be due to multiple entries of your video cards in the fs9.cfg file. Do you have more than one entry per card visible? If so, this might be damaging your frames. I fixed a friend's PC this past weekend and found this matter was one of the issues making his sim experience a misery: he had three entries for his single video card in the cfg file.Good luck!JS

Only scenery add/on I use is Ult. Terrain- apart from aircraft noted above.Everything remains perfectly fluid/ no stutters or pauses, and the FPS decline is only a sometimes thing- typically in rapid scenery changes such as manoeuvering for an approach- perhaps not surprising since my processor is feeding 3 different views to 3 monitors. The lowered (but still flyable) FPS then remains until "Refresh Scenery" is invoked which immediately bumps it back to normal.I'm surprised that this thread hasn't drawn more interest- I've always assumed that decaying FPS is a routine FS characteristic- otherwise why would MicroSoft have made "Refresh Scenery" a standard command?Alex Reid CYYJ

Just a thought,Try deleting your page file and rebooting. Then set virtual memory/pagefile to 2560MB in both max and min windows.See if this helps.Stu

Stu- Thanks/my virtual memory is set to Let System Manage- which works just fine. I've got no problem myself- Refresh Scenery is a command that works so well, I assumed it was in widespread use for diminishing FPS as you fly. Anyone who is troubled by lower than expected FPS while flying or even taxiing, should try it.Alex Reid CYYJ