About 2 years ago I had a 333mhz 64mb ram and ran gba and some psx at full speed(most the time) So you should have no problem with the right emulator.

Yeah, i meant i canMy computer specs are similar, 800mhz 386mb RAM.... and i cant play GBA, PSX, SNES, NES, Genesis, etc perfectly, with NDS emulation i suggest you get no$gba as its far more optimized than DeSmuME will ever be as its written in ASM
Do you mean can? Because I can run them perfect on my 256MB RAM computer