I even had the newer files replace the older files. Files can be found in the mingw-mame-w64-20140905.exe.
I was using the SDL_LIBVER = sdl2 in the sdl.mak.
QtCore4.dll QtGui4.dll SDL.dll SDL2.dll
waitvsync < Leave this off. Speed issue when this is on. Speed is at 96-100% when off. syncrefresh < Leave this off. Speed issue when this is on. Speed is at 96-100% when off.
Code:
K:\SDLUME>sdlmame64 svc Average speed: 50.69% (10 seconds)
K:\SDLUME>pause Press any key to continue . . .
Stick with the default settings. Don't even enabled the sdl2 in the sdl.mak file. Probably unstable at this time. I went back to the default setup. Talking about the sdlmame64 and sdlmess64.