Use generic USB 3.0 hard drive vs USB 2.0 drive?

I just ordered a refurbished Tablo 2-tuner DVR from the Tablo website. Next I have to buy a hard drive. Since, theoretically, USB 3.0 hard drives are supposed to be backward compatible with USB 2.0, shouldn’t I be able to buy any USB 3.0 drive and use it? And, if the drive works in a PC USB 2.0 port, shouldn’t it be Tablo compatible? The reason I ask is that I can buy a Chinese USB 3.0 320 GB hard drive for the same price as a USB 2.0 80 GB hard drive.

Duuuude, first of all, no-one buys a hard drive of less than a terrabyte anymore.

Secondly, Tablo has some specific models they favor more than others

That doesn’t mean others won’t be supported, they may or may not have issues.

Lastly, let’s get a bit technical. While there certainly is a great deal of compatibility between USB 2.0 and USB 3.0, the same cannot be said for power delivery over the two standards - USB 3.0 supports much higher current draws. The Tablo has a USB 2.0 port and as such can only provide as much power as the specification permits.

What does that mean for you? Well, if your proposed hard drive has an external power adapter, nothing - you only need to be concerned with the data compatibility. If your external drive is planning to get its juice over the USB connection, you should ensure that it won’t need more than the USB 2.0 spec can deliver - and good luck finding out how much your drive will actually need - most external USB drives simply fall back on their compatibility statement to specify that.

Oh, here’s details of power delivery over USB 2.0 and 3.0, in case you’re still interested.