Hi to all, I'm having a similar problem with massive drops of FPS from 60 (I use V-sync) to 10 fps, every 10 seconds (looks like a repeated process that is broken. Is not clear what triggers the issue but after 3 days of full testing (more than 20 hours of gameplay) I noticed that is activated during the landing when the wheels are approaching the runway, and after that, every 10 seconds. It can also happen above in the air, but the circumstances are not clear. Flying low or approaching forest area may trigger the issue (clearly a CPU/GPU overload triggers the problem). The characteristic of this bug is that once it starts, it doesn't stops, making the game unplayable. Also, is impossible to land the aircraft if the FPS drop happens in the same second you are doign touch down. Is really annoying.
I can confirm that graphics configuration has nothing to do (I downgraded all the quality options and I still get the same issue). Also the mods have nothing to do as well (I tested with and without them, after clean installation and same results). This issue happens with all demanding aircraft, like official modules F-16, F-18, etc. Because of this I understand that this is a general DCS issue after the latest patch (game was running good during the last 6 months).
Regarding core unparking, power management, tac view and all the tips mentioned in this thread, I tested all of them and they did not solve the problem. I'm attaching the log file just in case (you will see errors of textures and models not found, don't pay attention to that, I deleted many objects of Caucasus map on purpose to improve FPS performance of the map. The issue mentioned happens with and without these objects)..
dcs.log