We recently had a very good discussion on swap space and job suspension. I had a look at the Intel pages on Optane memory. https://www.intel.com/content/www/us/en/architecture-and-technology/intel-optane-technology.html It is definitely being positioned as a fast file cache, ie for block oriented devices.
I mentioned Diablo Technologies, who I think have gone out of business. They had available a DRAM form-factor high capacity memory device. This worked by tiering RAM memory - ie a driver in the Linux kernel would move little used pages to the slower but higher capacity device. I though the same thing would apply to Optane, but it seems not. Can anyone comment? I have probably said this on many forums - we are seeing the trend to wards higher and higher memory systems, which enable more detailed meshes, bigger models and in-memory databases. But do we need huge amounts of expensive and fast DRAM to do this?