Generally it's faster to render from one drive channel to another, or 2nd best, one drive to another on the same channel. A raid 0 setup is generally looked at by windows as one drive - you write to multiple drives at once, in theory overcoming any delays writing to/on an indivual drive. So if you're saying it was faster to render a source on your 2 raid drives to an ide drive (which was on another channel), then yeah, this might be expected.

To read and write a stream on the same drive, the drive has to read a segment, the PC/software does whatever rendering, and then the drive heads have to move to another area of the drive to write the new file, & when done writing, moving all the way back to the original file to read another segment. Going from one drive to another you get away from that.

Going from one channel to another, you have less of a problem with the channel getting clogged with the data stream - instead of one channel sending data both ways, one constantly sends and the other recieves.

RE: SCSI performance, some SCSI adapters are faster then others, and some drives are faster then others. A top of the line Adaptec card writing to a raid 0 array made up of late model 10,000 rpm or better SCSI drives would be hard for anything similar using ide to beat.

trivia: you can stripe more then 2 drives increaseing speed - you can also set up software only raid 0 drives in win2k & winXP (see Tom's Hardware for info)