Just bought a WD 1TB portable USB HDD. I plugged it in to do the first time Time Machine backup. The backing up process is ok: 20GB data in about 15 mins. But the encryption process is taking forever. It seems like a 2-step process: system copies your data to the external disk then encrypts the data. It's been 2hours but the encrypting only finished 27%. I guess it'll take at least another 5 hours to finish the whole thing. Will it take so long to do incremental backup as well? Every time I finish the backup in a few minutes but have to wait for hours for the encryption? Is it normal? What happens if i unplug the disk while encrypting is still going on? Will the encryption resume next time I plug it back in again? What's the bottleneck here? I looked at Activity Monitor, CPU's been very low usage. So I guess it's the USB2.0 that limits the encryption speed? Or the hard drive itself? Thanks!