I have done it with a 32Gb USB3 drive, I can tell you it is very slow. I have borrowed an Mecer Stick PC that has Windows 8 on it but I have not tried it as I need a free HDMI port and a powered USB hub. It also dont take PCI-x but was wanting to try it on my USB miners.
I might just go with a laptop HDD, as much as I would like a SSD, the prices are a bit high at the moment. Also I believe the regular HDD's have a longer lifespan, or so I've read.
