Backup/restore speed very slow, is encryption to blame?

I have just downloaded Duplicati and am running my first initial backup. It seems very slow to me (approx. 10 megabits/second, or approx 4.4 Gb/hour) . I chose the default AES 256 encryption and default block size of 50 Mb. I’m backing up only to an external drive using USB 3.0.

Is this backup speed normal? And should I expect around the same for restore speeds?

Also, I assume I will now have to continue with encrytion for subsequent backups and restores, correct? Since I’m only backing up locally, there’s no real need for encryption. So can I disable encryption once this initial backup is done, and proceed with future backups and restores unencrypted? Or must I delete and rerun my initial backup from scratch, this time with encryption disabled?

There are many factors that determine the speed of the backup, and no one will be able to tell you what the acceptable speed should be for you. Feel free to experiment with some settings to try and increase your throughput. I would suggest changing to hashing algorithm to MD5 and disabling compression.

On my computer which is a Xeon 3.4Ghz 4C/8T and SAS drives I get a backup speed of 70MB/s.

I am currently backing up (AES, zip compression level 0, 250MB blocks) from average class SATA hard disks (disk to disk on one computer) at 80 Gigabyte/hr.
Cannot tell about your machine, but USB often is a troublemaker in my world. I don’t think AES is your problem.
Have no experience if you should change the backups preferences for an already done backup.

Duplicati performance with lots of changes (such as initial backup) is often a bit slower than other solutions, however once the initial backup is done the following backups tend to be a bit faster than other tools due to the deduplication features.

The encryption is slowing things down a bit, but must likely it’s not a major part of the the performance you’re seeing. There are some other posts on the forum that go into how to speed Duplicati up - I think some of them do mention using alternative encryption options.

Additionally, if you’re using a newer canary (or possibly experimental) version then there are some options for adjusting parallel processing related to encryption.

Thank you all for your feedback and suggestions! :grinning: