On Mac OS X QuickSync can be used as well, but only with certain parameters, and we have very little control over what it does or even when it activates as this is controlled by Mac OS X. On Windows we have access to Intel's QuickSync for encoding and it works wonderfully. It's no secret that Mac OS X limits the access that developers have to the hardware, and without this direct access, less optimization can be done. The biggest hurdle here is Mac OS X itself. The only recent computers that fall into the real-quad-core range are the 15' MacBook Pros, iMacs and Mac Pros. MacBook Airs can have i7's in them, but they're ultra low power dual core i7's. By quad core we mean a real quad core i5, not the dual-core-with-hyperthreading i5.
Today we are releasing Game Capture HD 2.1 Beta 84 for Mac OS X, which adds support for the recently launched HD60 S.