Hello!  My apologies for not introducing myself in the new member forum, but I'm afraid I'm at my wit's end (not that it takes me long to get there).  Very recently I've been experiencing a periodic frame rate drop; doesn't seem to matter whether I'm flying or on the ground, or what airfield I'm at, or what the weather is like (I use Active Sky Next and love it).  The flight will run just fine for about a minute, then at 2-second intervals the frame rate will drop below 20 fps and will drop to almost the same rate each time.  I've tried doing a clean uninstall and reinstall, shutting down all the background processes I can think of, clearing my RAM cache, reducing all the display settings to the minimum possible (target frame rate 30 fps), turning off filtering and DirectX 10 preview, and overclocking my CPU, all to no effect.  My video card drivers are up-to-date.  I've also noticed the frame rate will stabilize again after I've closed the FSX window, but the drop starts again about 30 seconds later.  If anyone can help me I would be grateful--I really enjoy flight-simming and would hate to miss out!

Running FSX Steam Edition on Windows 10 (have the Acceleration Pack)
Dell/Alienware Aurora R4 Intel Core i7-3820 @3.60 GHz 8 GB RAM (Note: I've tried adjusting the AffinityMask and PoolSize parameters, also to no apparent effect) 

AMD Radeon 7500 HD driving a 1360 x 768 monitor

Thanks!

Mycroft/Chris (more than one Chris here, I'm guessing)
 

Hi Chris, welcome to AvSim. Check Road Vehicle setting. It's known to cause frequent stutters even with a very low setting. Turn it off and see if it fixes the problem.

As long as the sim is displaying smoothly, don't get hung up on frame rates.  If the sim is stuttering or pausing at periodic intervals, it could be the sim is loading the scenery for the area you are flying into.  Another possibility is a background process that is making use of the CPU and/or drive.  Anti-virus software is well known for causing pauses and stutters.  I suggest making FSX and any associated program exempt from anti-virus scans.

Hi, Ray and stans!  Thank you for your replies.  Well, as Emily Litella would say..."Never mind!"  I finally realized my CPU was overheating, so I opened up the case and found a whole warren of dust bunnies.  Cleaned all the fans and the liquid-cooling system radiator, now it works just fine.  You folks know your stuff, and I'm glad to be here!

Chris

Yeah, a dirty cooler will allow the CPU to overheat and that causes the CPU to throttle itself.