ForceCompositionPipeline keeps getting disabled when my main monitor is power cycled.

I’m on 64 bit Linux Mint, running the 415.18 drivers right now, though this problem has been around for quite a few driver revisions. (I’m not entirely sure when it started, sorry!)

I have a GeForce GTX 1070 driving a BenQ LCD BL2711U monitor running at 3840x2160 on DP-4, and a Philips 244E running at 1920x1080 on DVI-D-0. The following line exists in my xorg.conf (I can provide the entire file if anyone cares):

Option “metamodes” “DP-4: nvidia-auto-select +0+0 {ForceCompositionPipeline=On, AllowGSYNC=Off}, DVI-D-0: nvidia-auto-select +3840+1080 {ForceCompositionPipeline=On, AllowGSYNC=Off}”

This does seem to correctly turn the Force Composition Pipeline option on when my X server starts up, which is important to prevent hideous tearing any time I scroll a web browser or watch a video.

When I turn the BenQ monitor off, it’s still enabled, but when I turn that monitor back on again, my Philips monitor goes blank for about a second as the BenQ powers up, and once it’s done, the Force Composition Pipeline option is mysteriously switched off (watching from the nvidia-settings panel). Turning the Philips monitor off and on doesn’t seem to affect anything.

While it’s not the worst thing in the world, I can always go in and switch it back on every time, it would be nice to know why this happens and what can be done to prevent it. I have managed to stop it from happening before, but I’m not entirely certain what it was that I did which affected it, and it seems to be back.