MAME starts having hiccups after running for a few hours

[fleskebacon]

I have noticed that my MAME starts having occasional small hiccups when it has been running for a few hours. I'm running regular MAME 0.263.

The hiccups are like small freezes, just a fraction of a second, maybe just like a frame or two. It seems totally random, not related to any input or anything that's going on i the game, and with 5-30 seconds random intervals. I've had this in several versions of MAME now, and it occurs in any game/rom, so reckon it's most likely not MAME itself causing this, rather some other stuff interfering with it. But I'm not quite sure, because if I restart MAME, the hiccups go away.

I'm on Win10 64 bit, running an i5-3350 and a GTX1050 with Gsync, which is very, very smooth when these hiccups don't occur. Vsync, triple buffer etc are off. I have turned off all power saving stuff I can find, but I'm a bit lost here. If there was something obviously wrong with my setup, the probem would probably be constant and more severe. But this seems to build up in magnitude as long as MAME is running, and disappears at once when it's restarted. Could resemble a memory leak, but I kind of doubt that MAME has had that kind of problem for several releases?

Any ideas what this could be, and how to fix it?