Ok, I just compiled one of my home made SDL demos in 320x240 resolution. Running it fullscreen seemed to keep the desktop at 640x480 and just run my demo in the middle of a black screen. Doing xrandr -s 0 before running it made it seg fault, so for this test I just left it at 640x480 (if anyone knows why it seg faults and how to run it in true 320x240 res, please let me know).
Running in landscape - the demo ran fairly jerky - and it shouldnt because its very simple.
Running in portait - the demo ran perfectly with a doubtless speed increase.
Once again, I ask why this is? I could write my games and demos sideways, but that would make porting them hard and kind of silly.
Thanks,
Phill