If you need to re-upload your Backup to Backblaze, there are a couple of best-practices that you can use to increase the speed at which you upload. If you take a look at the Performance Settings on your Mac or PC you will see that you can toggle both the “Automatic Throttle” and the “Number of Backup Threads” for your backup. Increasing one or both of those will allow you to, in some cases, dramatically increase your upload capacity (while using more of your available bandwidth).
Performance Settings Mac:
Performance Settings PC: