I don't think that would be my main complaint. Sticking optane in a dimm was just awkward as hell. You now have different bits of memory with very different characteristics, & you lose a ton of bandwidth.

If CXL was around at the time it would have been such a nice fit, allowing for much lower latency access.

It also seems like in spite of the bad fit, there were enough regular options drives, and they were indeed pretty incredible. Good endurance, reasonable price (and cheap as dirt if you consider that endurance/lifecycle cost!), some just fantastic performance figures. My conclusion is that alas there just aren't many people in the world who are serious about storage performance.

Can Linux differentiate that different dimms are different? Or does it see it all as one big memory space still?