I think the question was more tuned to physical ram disks, but I'm not sure.

Either way, how many terabytes were being written each day? And how much can your drive take? It looks like I could go pay $60 right now for 600TB of endurance, and $35 for 200TB of endurance. If you already have the extra ram than go for it but it doesn't seem like a setup to make on purpose.

Maybe your backup system has far more writes than mine? I have terabytes of backups but the average written for each daily backup is about 10GB.