How to restore files on top of what's there? in Professional Posted August 22 · Report reply 16 hours ago, MrPete said: .... .... .... ....Bit Rot and Drive Replacement: In reality, bit rot can happen on ANY drive. In no way does bit rot imply a drive that needs to be replaced! Just for example: Consumer SSD drives retain data "perfectly" for approximately one year (if you've not overwritten a sector) before bit rot begins to show. It's worse for enterprise SSD's (because they are focused on performance over data retention.) This is not exactly advertised by the industry. Dig into the latest research and you'll discover the reality..) NOTE: some mfg's MAY be compensating for this and taking care of it in firmware... but I have yet to see such workarounds documented. And YES I have been harmed by this. Consider: what is the one sector on a drive or partition that NEVER is overwritten?... (How to avoid this: regularly rewrite every sector of an SSD. I do it about 3-4 times a year. I could point you at the (very!) technical research work that underlies what I wrote above. I agree that it's more than a little surprising. Thanks for the info, MrPete, For hysterical reasons I have been alternating between the use of two drives for Retrospect versions on my "cheesegrater" Mac Pro "backup server", one HDD and one SSD. ATM I have Retrospect Mac 16 on my SSD, with Retrospect Mac 15 on my HDD. However I've elected to keep my Catalog Files on the HDD, just in case I have to switch back or upgrade forward. Retrospect Inc. (should I still call them that?) is kind enough to provide new point-releases of Retrospect Mac 16 about every 3 months, which I'm sure they do just so I can refresh my SSD. I was vaguely aware that SSDs had a shorter lifetime than HDDs, but I thought progress had been made on that problem. Now you're saying it hasn't, so what was good enough in the 1970s is still better over the long term than its replacement. Spinning rust forever!