Yes, and yes. Same physical USB drive, separate partitions.
My previous installs were from either a separate USB drive, or a 4GB USB memory stick, and they were installs to the 16GB STEC SSD
. Due to the space crunch on such a small SSD
, and the fact that (at least initially) I wanted to be able to boot back into leopard on the internal SSD
, this time I went for the external USB drive.
Comparatively, the disk speeds I've seen on the Mini 9 USB 2.0 ports have been as good as the firewire ports on my PPC powerbook, or faster, and much faster than using any USB drive on the PPC powerbook which only supports USB 1.0. I've been using external USB drives on the Mini 9 for 9+ months and never noticed anything as slow as either the DVD copy or the install speed until today.
Since the install/upgrade only took an hour on a real Mac, and processor speed is not usually a significant factor during a system install, I was stunned by the 10 hours it took.
Leopard, USB => SSD
only took a couple of hours on the same machine.
Since the SL install, I have also done a second leopard install, booting from partition 1 on this same USB drive, and installing on top of the snow-leopard install image on partition 2. This took nearly 5 hours. Again, longer than expected, but half the time of the SL install. I still can't believe 10 hours. (And I still need to do the combo upgrade to 10.6.2 or 10.6.3).
This leaves me with 10.5.8 on the SSD
, 10.5.4 (so far) on the USB:Partition-2, 10.6.0 (so far) on the USB:Partition-3.
I think there's more to it than just USB speed. I don't recall seeing anyone else complain about the time it took for the install. So, how long did it take others to do the initial 10.6 install, and how much additional to do the combo upgrade?