The present version of the GPU emulator cannot be
configured to scale the image. -- by any means...
Otherwise its performance is very good, even better
than the hardware accelerated OpenGL driver. (which, in
its latest incarnation, crashes and locks X-windowze).
The flags I am using are:
CFLAGS = -g -march=athlon-mp -pipe -Wall -O3
-ffast-math $(INCLUDE)