Are there known causes for instant framerate fluctuations?I noticed during my last few flights that my framerate display (shift+z) does not show a steady framerate number. I have it locked at 25 and it used to stay there most of the time but lately it goes up and down every second even when there

No ideas? :-(No one ever experienced something like this?

Does it happen in a static view, or are you changing views, looking around VC, etc.? I notice my framerates change a bit when I look around or change views. Usually not as drastic as yours (just a couple frames down from a lock at 24), but they do shift around. Its not unusual for me to drift a couple frames up and down just flying along and maintaining the same view.

Well its nothing unusual for most folks that don't have an overabundanceof CPU power.The main culprits are; AI traffic, online weather updates, other programsrunning with FS, and any Windows or other background processes running. Antivirus and indexing being two of those that come to mind.

Thank you both for your suggestions. :-)It does happen with static views... It even happens with FS9 paused!On a side note, pressing "Q" to disable sound makes no difference.I agree that my 3.4 Ghz P4 is starting to show it

It sounds like something is running in the background. Even leaving your task manager window open can have momentary dips in the fps as it updates.I shut down spy-sweepers and McAfee and use autostart.Lock your frame rate to a fps value to achieve a V (shift + Z) of 1% or less.Daryll

I've found in the past that some particularly obnoxious examples of spyware can cuase these sorts of problems too.

Thank you all for the help.Regarding spyware, I run once a day Ad-aware SE Personal and Spybot Search and Destroy.Everything these programs detect is removed immediately. :-)I also use AVG antivirus which I close with FSAutoStart when I

Try defragging your hard drive if you haven't already done so.Regards, KendallDell 8400 3.2 GHZ H.T.800 FSB/2MB L22 GB 533 DDR2X800XT 256MB/Catalyst driver - 6.9's6x Adaptive AA/16x HQ A/FIntegrated SoundDual Monitor: Dell 2405/1905CH Yoke/Pedals

Thank you for your input Kendall but I defrag at least once a week or everytime I install or uninstall something into my system using O&O Defrag Complete/Name method. :-)

Hi BradJust a suggestion try a little program called memstatus and see what's happening to your CPU and GPU memory whilst FS9 is running. I had just purchased a Dell 24" monitor and I am running at 1920x1200 resolution and found that although my cpu usage was fine, at peak times I was hitting 97% of my GPU memory (nvidia 7900GTX 256Mb). I upgraded to a 7950GT, 512Mb and these fluctuations were far less. It may not be the same in your case but it is worth a look.RegardsPeterH

Thank you Peter.I

After a 2 hour flight using some of my favorite addons these are my findings:I need at least one more Gb of RAM! :-lolhttp://forums.avsim.net/user_files/160012.jpgNow seriously, I don

ram usage will INCREASE as a new terain area comes into view, and DECREASE as one leaves view. This means that it will visibly vary but only by the size of 2-3 Mb per texture at the most. Also, memory usage varies significantly as the number of AI aircraft within "view" varies. There is a variable being managed for each AI plane, plus somewhere a table is managing ALL of the AI planes and deciding at any given time and place which ones need to be rendered, if not graphically, within the ATC system. Note that FS calculates position of aircraft sometimes as far as 200 miles away (all aircraft in your current controlled sectors and any you may pass through) and this can cause large fluctuations in memory EVERY FRAME as a plane can easily pass in or out of FS's "Handling" range.I'm sure there are other reasons, but from a programming perspective, those are reasons that I can predict.-Brian

Thank you for your explanation Brian but I don