QUOTE(lantus @ Jun 6 2011, 04:09 PM)

quite simply yes. the mame codebase runs poorly on anything outside of an x86 CPU. There is no dynamic recompiler backend of anything outside of intel currently - and there are no plans to be as far as i know.
Without getting too technical both the PS3 and 360 CPUs handle in-order only execution. while x86 cpus handle out-of-order execution. What does this mean? Basically as code gets executed, the 360/PS3 cpus will stall over and over while it orders the instuctions in a in-order format that is required. On a PC, this does not happen. They (MS/Sony) provided in order only CPUS in their consoles to reduce costs/chip die size. To work around the performance implications of this they gave the xenon cpu 3 cores to work with.
Now, mame and every other emulator out there was developed on a PC. Running PC code on a PPC chip just wont perform well. Any dev who has made 360 homebrew from PC source will tell you the same thing. Why do you think there is no N64/Dreamcast/GC/Wii emulators out there yet?
On top of that, over the years the mame codebase has become slower. This is a fact. Even on a PC. Mame360 performs worse than Mame 0.72 because its a higher revision of the code. The mame devs have no concept of performance implications its purely about emulation accuracy. PGM roms run at 35fps on my mame 0.141 build, yet they run at 60fps in FBANext - and the driver/cpu code was taken from mame in the first place.
Now having said that, yes with optimizations/multithreading theres no reason why a 360/ps3 build couldnt run well. But now we have to deal with 1) spending weeks/months modifying the code, and the expectation to keep that same codebase up to date with mame revisions. It would become a nightmare. I personally dont want to deal with that.
hey lantus hows that patch coming along?