I was wondering wich is the best solution to keep my DAW efficient:
having a single PC with multiple ATA 100 hard disks (1 master for operating system, 2 slave for audio and sample streaming), I'm currently using a dual boot system with one partition for general purposes and one, much more clean, for DAW, both on the master hard disk.
Any differences in terms of stability and data transfer rate using instead a mobile rack solution, with two hard disks, one for each task?
Most folks do that with profiles. Unless you need to maintain different OS's or patch levels.
I use plugable drive bays for my audio and sample disks. Just make sure you get a good one. I've tossed some el-cheapo plastic brands over the years. But have had better luck with KingWin aluminum IDE KF21's which I highly recommend. I see they now have aluminum SATA models too.