I bought a new 3 TB My Passport Ultra drive Monday. Removed my old drive and plugged in this new drive to the USB port of my 3TB MyCloud. So it’s running USB 3.0 speed.
I have 1.7 TB of data to backup so I started it at 6:30 PM Monday night. Well it’s been over 30 hours now and it’s only 51% done. 860 GB of data has been transferred so far.
What gives? Why is this so slow? My Passport Ultra isn’t really a slow drive. It’s running USB 3.0 speed. I could transfer 860 GB of data to the MyCloud device in like 7 hours over the network. I was getting a good 30-40 meg per second over the network. That’s around 2 GB a minute. 120 gigs an hour. Would take around 7 hours. Not 30 hours over USB 3.0. Shouldn’t USB 3.0 be faster than gigabit network?
Coincidentally, I did a backup of my media files last night. Having recently changed to a new desktop PC, the permissions on my backup disk were all wacky. I tried fixing them, but decided the easiest way was to format the drive, and start a fresh backup (a bit dangerous, as the NAS could have failed whilst performing the backup…).
It required a 795GB, 115k file transfer, using my gigabit network. It took 13 hours, which works out at about 17MB/s average. Whilst the backup was running, I could watch the reported transfer speeds during each file transfer (FreeFileSync displays that info). For the small text and document files, the transfer rate is poor, as a lot of time is spent messing about with the directory entries, leading to low link utilisation. But for the bigger files (especially some multi-GB ISO files), the transfer rate peaked up into the high 40s. Since the backup was mostly FLAC music files, I’d estimated the average by eye to be about 18MB/s, so the actual 17MB/s was about right.
The target disk was a USB2 device on the PC, not on the MyCloud.
