OK. I figure that since I am seriously into flight sims I am going to start my search for a solution here. Bear with me for a sec - I need to set some stuff up.First I upgraded my machine a month ago. AMD 64 3800+ X2 processor on an ASRock motherboard w/ 2GB DDR PC3200 Ram and an ATI 9800 Pro Video card (128 mb). I then upgraded to add an ASUS A8N SLI Premium motherboard with 2GB Samsung PC3200 DDR Ram and 6 GeForce 6600GT cards in SLI. Nothing really unusual about that BUT in FS9 (in both configurations), I saw periodic flashes as the FPS dip to 1. Watching the FPS display sometimes gets me numbers as high as 178. Strange..I also fly WWIIOnline a whole lot. Now I do not see similar flashes in that game but watching the FPS meter I see typical numbers around 60 FPS (with the latest rig in a busy environment) AND spikes ranging from -64 FPS through the roof to 180+. These seem to be typical spikes - I'll see numbers around 60 then a single value at -43 then back to the 60 range then I might see 192 or -16 at some seemingly random point.I think that it may have something to do with the dual core and the way that the FPS is being calculated. I don't know, however, and I am grasping at straws. In FS9 it is a problem because once the sim detects the 'drop' in frame rate it unloads textures and I get a momentary flash as textures drop to their simplest form. Then, of course, the sim detects the 'correct' value and the textures are re-load/de-displayed.It makes the sim (fs9) particularly unflyable. Other sims seem ok because they are not dynamically trying to adjust things as much (or as often) as FS9. Any hints? Any suggestions on where I can go for further info or other tests that I can run?

Have you tried limiting the frame rate to some reasonable value, say 30 FPS or so? That might smooth things out a bit. R-

is this a default FS install? It seems like you are having other issues such as duplicate afcad files, bad landclass bgls with texture folders in the same location, bad ai traffic, or something.Also a duel core means nothing for flight sim. In reality, it only uses one processor so you might see worse performance than someone with a comparable chipset but that has a single core processor

SLI could be your problem, FS does not take advantage of SLI at all and in some cases and actually cause a FPS drop, like you are experiencing, if your system is mainly for FS, get 1 really high end video card, 7800GT or X1800.

FPS are limited in the sim setting to 30. It's a new install (reinstall).A post on another forum is noting that there is a (apparently) known issue with the ASUS A8N-SLI Preimum motherboard and the AMD X2 chips. Another post mentioned drivers for the AMD chips. I'm checking that as well.I am investigating further.FYI I don't think it is the sim (FS9) or the settings. I believe that it is firmly hardware rooted since I am seeing abnormal behaviour in more than 1 sim.

No issues here with an X2. No special drivers installed either.. :)

No issues at stock speed with my x2 3800+.Oh, and no issues overclocked to 2.6Ghz :-samurai Regards,

x2 4400, geforce7800, no problems. Frame rates 30 and more.

FYI: Looks like my problem was solved with the AMD driver install. Again, for anyone keeping track I believe this issue is more to do with my process/motherboard combo than anything else. This post was more of an information gathering tool for anyone in a similar situation to my own and maybe for AMD Dual core owners.As a final close to this thread I submit the following link - just for information purposes (again, AMD Dual core related): http://www.hardforum.com/showthread.php?t=983781

Yes some mainboard seem to have issues with dual core CPU:s. But nothing a new bios can