Comment 13 for bug 1532202

I just noticed in comment #7:
    4. "--disable-overlays on" reduces FPS further, but seems to cure the jerkiness
which reminds me that multi-monitor and bypass/overlays are both scenarios that may each require an extra buffer (triple buffers). And in some cases using both at once necessitates quad-buffers to keep up.

So does this help?: --nbuffers=4

I'm thinking only in a nested setup would you be sure that your multiple monitors are all being overlaid/bypassed, so quad buffers may be required there.