I’m running Ardour 5.5 on a Mac with only Ubuntu Studio 16.04 installed. The Mac has two physical hard drives. I read or heard that it is better to keep the DAW and operating system on one hard drive with sessions stored on a second drive, so that the computer is not accessing the same disk for operating system function while reading/writing to the same drive. As a result, I have been creating and storing sessions on a separate drive from Ardour/operating system. Both drives are internal. Is this a problem for Ardour?
Ardour has no problem with using either drive. It is currently possible to use both. You may get better performance from one of the drives, or the other, but it isn’t possible to make any simple rules about it.