0GB OWC Mercury Elite Pro Dual mini bus-powered FireWire 800 & USB 3.0 RAID Storage Enclosure

I now have two of these (USB 3.0), and 3 of the older eSATA version. They are easy to setup and convenient for portable drives. I only use one as a portable. The others are stacked on a shelf on my desk. I don't have USB 3.0 yet, so I can't speak to how well it works. I use Firewire 800 on the two of these I have. One has a pair of 256GB SSDs (spanned), and the other a pair of 1TB HDs (mirrored).

Received this drive today and i was impressed by the size and finish of the unit. After spending some time with the OWC technical support i was told that this unit is NOT bus powered by USB and requires a separate 12v power supply. It is bus powered by firewire only. However the unit does not come with a power supply.Unfortunately i have no way to report on the performance of the unit as i have no way to power it on. Although if i can get an adapter i will update this review accordingly and it may get a star or two back.I was extremely disappointed that this information was not included on the product description page. The drive looks like it has promise, but currently is a very pretty brick.**Update** I (frustratingly) purchased an external power supply and the unit is currently working fine. I tested by pulling the drives and checking that the unit rebuilt, which it did fine, so it seems to be working as expected. My test process was to turn the unit off, pull one drive then restart the unit - check that everything still worked fine - switch off and reinstall a new blank drive (identical type), then switch on - then check that the unit rebuilt the drive and regained redundancy. In all but once case the unit worked perfectly. For the case that did not work, i replaced the 'failed drive' with one that i had previously used in this unit to test and it was not blank - this time the unit appeared to the OS as a new array and the data was lost. My advice is that if you ever have to replace a failed drive in this array, ensure that it is completely blank. I have upgraded my review from 1 star to 3.Also, of note, it is difficult (but not impossible) to tell when the drive is finished rebuilding after a failure. The only indication that the drive is rebuilding is that the blue drive lights flash faster, which is exactly the same indication as when the computer is reading from the drive. The only way to tell that the unit has regained redundancy, is to not access the drive with the computer and if the drive has finished, the lights will be solid blue. It seems to me that it would have been pretty straightforward to make the drive failure LED (red) continue to flash until the drive is rebuilt and redundancy regained, and i would suggest to OWC that they make this addition to future versions.

I suppose I should have looked closely at the pictures....This is NOT usb powered and it does NOT come with a power supply. So, when I got this device it is useless. However, the box says it comes with a power supply and it did not have one. My first disappointing OWC order in many years.

Was disappointed that it did not support JBOD. return to Amazon for refund.

Easy to setup. However, unable to power up with USB only. Will required external power.

Purchased 2 Seagate Slim 2TB backup drives to harvest for disks. They were extremely easy to disassemble. Everything went together easy and it works great!! Probably will do another one next month.

NOT BUS POWERED! Despite what it clearly states on page two of the manual, this enclosure can NOT be powered via USB. The advertising, and even documentation is very deceptive. Attempting to get OWC to reconcile this error has been futile. Their answer is to pay extra for what they should include. Very disappointed in this company that I have patronized for many years.Update: A representative from OWC contacted me and apologized for the service rendered by their support tech. They have promised to update their information to reflect that the enclosure does not support bus powered USB connections. They also sent me a power supply.While I certainly appreciate the effort on their part to correct the situation, I can still only give this product three stars as a "portable" enclosure that requires external power is not terribly useful. Very few computers have Firewire 800 ports.

It's been working great for 2+ years.