I've had several USB external enclosures. The first was a combo USB HD/MP3 player called a RooPaq. (Usb 1.1) This unit was self powered, and I never had any problems with it.
My next enclosure was a an ION enclosure usb2 from IOGEAR, which I installed at least 3 different 2.5" drives in at different times. This unit could be powered by the USB port alone, but I found it could be under powered easily, esp. by usb hubs (even powered ones.) It also came with a cable to pull power from a PS/2 port, which was often needed. I should point out that it was obvious that some drives did better with power requirements than others.
I also now have 2 5.25 usb2/firewire units I grabbed for work that have been great. They do need A/C power, but perform flawlessly 100% of the time. Got them at Comp USA on sale - Manufacturer name was "Acom Data" - basic looking enclosure, came with western digital drives. I love em here at work, been using them to do installs, ghost machines, etc on all kind of machines here usuing both usb 1 & 2 modes. Never had a problem yet.
The only culprit I've ever run across with using external drives, is the under-powering of the unit when relying on the usb port alone for power. That can result in a bunch of symptoms from the obvios (drive not spinning up completely) to the odd, (problems occasionally on writes, sometimes scrambled data.)
I should note that I have also ran into the under powered problem using USB memory drives. (once causing total loss of the existing data)
Bottom line, make sure you port is supplying enough power, or use an a/c or ps/2 power adapter.
Caprel :thumbs:
