galaxy ace problem

[vitality19]

stock 2.3 for me is the slowest, laggiest and buggiest rom ever, so I don't recommend using it for heavy 3d games, emulators (the only good thing about it is battery and hardware acceleration in video)

CM7 is much more faster, but the bugs with hardware transform remained
In CM9,10 hardware transform bug disappeared
so a good graphics driver can mean a lot

There's an unofficial port of CM9 for your device (serch here) http://wiki.cyanogenmod.org/w/Unofficial_Ports that you could try, although I'm not sure if it'll sove the problem, perhaps the ARMv6 itself needs fixing