I have some theories here, but I wanted to run this scenario past the good folks on this board to see what thought people have on why this happened... I have these two machines: PowerMac G5 Quad w/ 6 GB memory and WD 400GB HD MacBook Black - stock with 2 GB memory I took a video I was compressing for the web, and did a quick and dirty edit in iMovie. When finished, I exported both to H.264, same settings. The PowerMac took ~35 minutes, the MacBook took ~140 minutes. Why? Max.