That's exactly what I've got in my system: md0 = /dev/hdb1 + /dev/hdd1 md1 = /dev/hda4 + /dev/hdc4 non-RAID partitions are on /dev/hda1, /dev/hda3, /dev/hdc1, and /dev/hdc3; /dev/hda2 and /dev/hdc2 are swap.
For some reason, I had assumed you were using a PCI based ATA controller.
From the above, it looks like you are using a motherboard based controller.
I have done some timing tests of couple of those, and in particular on the Intel motherboards I use, the 2 different IDE channels definately impact each other. ie. They are not independent channels, but share some common piece. So you may not be buying anything by doing raid-0. If you have $50 to try a PCI -based controller you should see the speed improvement you expect. I have tried SIIG and Adaptec PCI cards, the Adaptec is slightly faster. The 3ware controller should be even faster, but I have not really found that to be true, and they are not cheap. Greg -- Greg Freemyer