Performance issues with MS Flight Simulator X on DirectX 9 are common.
Performance issues with MS Flight Simulator X on DirectX 9 are common.
I've been using MS Flight Sim X with DirectX 10 preview for some time now. Thanks to that setting, the game runs smoothly even though it's quite old. Recently I added some new aircraft add-ons that don't work with DirectX 10—using the preview textures would show them as white. When I disable the preview and run the game with DirectX 9, the add-ons function properly, but performance drops. It seems the issue might be with the add-ons themselves rather than the graphics settings. I've heard the GTX 970 has trouble with DirectX 9, so that's likely the case. Is there a way to boost performance? Also, it appears FPS dips only when you're on the ground with lots of buildings, parked planes, or taxiways—everything seems fine in flight at cruising altitude.
FSX feels unusual. Dx9 depends entirely on the CPU from what I've noticed. The game demands high clock speeds right from the start. When everything is pushed to its limit, I see around 30 frames per second near the scenery with my 5820k OCed boosted to 4.5 GHz. My CPU usage stays near 100% on just one core.