I think that's probably the next experiment, I'm not sure if I'd got for a HDD or a very small USB SSD to keep the power usage down - at the moment it's under 0.5W, a HDD will be several times that.
Pandaboards run much faster with USB hard drives instead of SD cards. That's what I hear from lots of knowledgeable people, anyway. I've not actually run any benchmarks though.
Agree with that. I use a pandaboard as a build server and I felt it is a lot efficient to use NFS than running off an SD card.
Ewan, have you tried USB HDD instead of SD card?