Slow backup from Ssd boot drive using Retrospect software

I updated my system from a Dell XPS 8700 to a Dell XPS 8900. My 8700 had an SSD boot drive and 3 internal HDDs and several USB externals for backup. It worked well for backups. 8900 came with SSD but it was not setup as boot. Boot was a HDD. I moved operating system to SSD. Now when I backup, the HDDs transfer data at a reasonable rate, usually several hundred MB/min. The SSD is ridiculously slow, running at sometimes 0.5 mb/min. Rarely is it in triple digits per minute. It took over three days to backup 100 gb from SSD to external HDD? The other internal drives backup normally to the external drives. I have used Retrospect backup software for years and even tried updating to the latest version. It made no difference. Any ideas why the "fastest" drive would be the slowest to run backups?

I finally had a chance to realign the partition and it works much better. Retrospect is copying files at 3000-5000 mb/min instead of 200-300 mb/min. I used Partition Wizard an it worked great. Thanks for your help.