MAME Cloning Displays and 1080ti - 94%-100% speed. Why?

[delt31]

I'm cloning TMNT to two monitors and b/c of it, the sound will stutter here and there so I pressed F11 and noticed it's 94 to 100% back to 94 back to 100 all the time.

I can't imagine how this is too taxing to do at 100% with my 1080ti and nice CPU.  Anything else I should check to see how to fix?  I made sure refresh rates are identical.

EDIT - did some additional testing. If I disconnect the other display, the remaining display plays it 100%.  If I connect the other display in windows and have it extend or close, the % drops to 98 or 94.  I wouldn't think adding in another monitor in windows would cause this.  Still trying to figure it out.  I'm trying to show the same picture on two screens so the kids can do 4 players (two people looking at one screen)

Thanks

[delt31]

Resolved this myself.

It was the Oculus rift I had plugged in.  When I removed that, I also split the signal so the two screens are shared and I have the tv as the second output.  Works well 100% when I just use the one output with the split signal.