Apple has faster hardware and the best so far are those dual Xeons at http://www.apple.com/macpro/
That will drag the time down.
PS. On your machine? Try more ram and don't run anything you don't have to during the render.
Does anyone know how to speed up encoding on iDVD, when I try to put my home movies on it takes about 5 hours. Now I am running a 1ghz G4 with 1gb of memory and 10.4 with a Lacie 16x DL DVD-+R drive on 16x disks. Is there a certain format that the movies should be in like .DV or.MP4 or .MOV......please help me, thanks much