Your thread wasn't approved, because it fits in the Black and White Emulation Help Thread, stickied in the Emulation forum. But I can give a bit of insight- the speed also depends on your computer. I know for me I could technically only play Black when nothing but the emulator (no$GBA) was open. So that might help, but would be a nuisance. Also, I found altering the 3D settings on No$GBA also slightly affected the speed, for the better. I'd recommend posting your question in the thread anyway, you could probably get some better answers. :)