How to Achieve Optimum Backup Performance? in Retrospect 9 or higher for Macintosh Posted February 22, 2018 · Report reply A few comments: The amount of data moved is the biggest factor in backup speed. I am experimenting with grooming to do what I think you are doing. Rather than doing a recycle backup , I've thought about grooming the media sets down to one backup. That way, you never really do a "full" backup - much faster. Firewire 800 is not so fast these days. For some operations, disk speed is key. Thunderbolt drives may be the ticket. For many things on Retrospect, CPU speed of the server is the bottleneck. Make sure you have plenty.