You mean real XBOX "roms" (=XBOX games) or those for systems emulated _on_ the XBOX? In the first case, i call BS and you probably don't know what's the situation regarding XBOX emulation. Even the cxbx (2)/dxbx guys went not too far with their attempts on relatively powerful machines running Windows. It's the nature of HLE together with all those different XDK versions that need individual adaption, when the emulator uses HLE (actually mapping XDK calls to WinAPI) to shows _some_ performance. See cxbx compatibility.