Yes, I compiled for faster code and 600Mhz. I read something about a USE_VIDEO_PLL but I am not sure where or how to set that.
Not sure what you mean with 4mb, the wads I got from gog are way bigger:
DOOM.WAD - 12.408.292 bytes, the version from gog
DOOM2.WAD - 14.604.584 bytes, the version...