Hardmac reports on some testing done by Christophe Ducommun, developer of DVD creation software Moviegate. When optimizing his app to take advantage of Grand Central and OpenCL, the speed improvements were remarkable. For what its worth, the following test was done on 2007 quad core 2.66 Ghz Mac Pro with a GeForce 8800 GT.
150 frame/s for encoding in MPEG-2
70% CPU load for decoding
130% CPU load for MPEG-2 encoding (ffmpeg)
104 frame/s for encoding in MPEG-2
165% CPU load for decoding
100% CPU load for MPEG-2 encoding (ffmpeg)
That’s about a 50% increase in speed, Hardmac writes, “a rather impressive improvement without changing any component on the hardware.”