Unsure if anyone has posted this in the tons of threads about this issue. I am not sure if the devs have ever gotten to reproduce this bug.
I have noticed with several longer campaigns such as Warlords, DUWS, etc... that the many AI attacks and such overload the memory. Mods such as Antistasis Altis, which have an adjustable spawn zones seem to help the problem unless you linger for a long time in the spawn areas.
Using Resource Monitor and System Process, you can see the memory climb higher and higher. When it approaches your threshold where it needs to start writing to the disk, this is where the fps drops. Pausing the game is no help as the read\write to the disk won't slow down and the memory usage keeps going. At this point, trying to save or do anything else in the game will cause a crash with out of memory errors.
Watching the single player campaign with the above tools, the memory is released at each load and save. With 4 gpu memory and 16gb system, anything close to 3.5 of memory usage will start the writing to disk and the immediate fps bug with me. Leaving it run for several hours paused in the menu is no help. Still shows 100% physical memory usage and alarming hard disk access. I have seen 15gb of total usage from all memory before. (A lot of IO activity, worry about the SSD physical health with this if it keeps going)
I realize that lots of mods, AI, etc... is being ran at the same time along with weather, time of day, ballistics, etc... but the read\write usage from the start is very high with mods that add a lot of AI spawns.
Simple test would be to run all the RHS equipment mods, Antistasis Warlords of the Pacific and then open Process Monitor and Resource Monitor, start the scenario and run within 1km of a zone, wait for the factions to base attack. As earlier, if you even pause the game, the memory climbs higher and higher and will eventually trigger the read\write to disk and the fps bug.
The bug is not mod dependent but mods make the problem quicker. Still the same thing with more than a few mutiplayers and long sessions. As most scenarios end or time out before the memory runs, starting a new session will fix it. Only extended long sessions with AI or multiplayers in which the game is not restarted or saved worsen the problem.
No malloc, page files (which you shouldn't really have to touch), system graphics settings, etc.. will cure it. Only makes the time until the fps bug lessen or quicken.
Question being, is there a reason why the AI and all the graphics associated with AI attacks still stay in memory? Even cleaning up bodies, equipment and damaged buildings and vehicles in a scenario doesn't help. Everything is held in memory and not saved to the hdd?
Going 64 bit will help this problem, but I'm afraid the underlying issue of storing things in the memory will still be a problem after a certain limit. :(
Link to https://technet.microsoft.com/en-us/sysinternals/processexplorer.aspx what I have used in the past to debug leaks in dll mods for other games.
