I had got a little fed up with FsXA because I was having a freeze (or pause if you prefer) after about 20 minutes flight time with the image frozen but the sound loop continuing. The sim would resume after about 10 seconds (average) until approx another 20 minutes when the same thing would happen.
Stutters and micro-pauses were virtually eliminated by locking frame rate in NI (at 23.5fps??) rather than in sim. I have also experienced the odd ping from FSUIPC telling me I was close to a ctd and oom message but the 10 second freeze ups are still a mystery.

So I ran FsXA windowed with the JF Stinson (as a fairly light model) and a pop-up vas monitor with frame rates displayed to see if I could notice a frame rate drop or vas peak just prior to the freeze. Neither measurement faltered for a second, which I would expect if the sim froze while drawing fresh scenery. So could it be something my pc was throwing out every 20 minutes that could be causing the freeze? I disabled anti-virus, and virtually everything else I could think of without success.

My settings are conservative with traffic at around 10%; TEXTURE_MAX_LOAD=2048 and lod radius at 5.5.

Any thoughts and have any of you had a similar experience?