Never had this happen before, just started today.
Occasionally in tactical mode the game is freezing for a couple of seconds, then it resumes as normal.
There doesn't appear to be any pattern to it, it can run fine for 5 minutes then will freeze up 2 or 3 times in a few seconds, then run fine again, freeze once, run fine again etc, in my last mission which lasted about 1.5 hours I'd estimate it froze around 20 times.
The only setting I have played with in the last few days is 'cores used' which I changed to '4' when I noticed the game running on a single core. This didn't fix that issue so I then reverted to 'maximum', which is how I've always had it and the game went back to using all 4 of my cores, however, since then the freezing has begun, although it's probably unconnected.
Any ideas?
edit
I am playing the Krasnaya Polyana campaign which I haven't played before, is that a particularly demanding map? I played Shilovo with no problems and I know that campaign can put a lot of units on the battlefield and definitely puts the CPU through it's paces but don't recall any freezing, FPS drops yes : ) but definitely no freezing.
I'm hoping it's not a hardware issue, haven't noticed any problems with my other games, played Arma 3 today for example and no problems there.
Are you sure something like a virus scan or maybe some auto defrag deal was running in the back ground? If I get a persistent stutter going on its usually some program in the back ground doing something. Usually my anti virus software running a scan at a stupid time.