Internal drive is very very bad.( and these figures are just averages - not deviations, the internal drive has poor consistency ).
Raptor, and scsi 10k and scsi 15k have close performance.
scsi 10k is slightly faster with some codecs.
Only dv-ntsc will give close to 30fps performance on all 4 layers.
DV-NTSC is slightly faster than DV-PAL- the difference is important