alt Hacker NewsI never understood what they're meant to do. Intel seemed to picture some future where RAM is persistent; but they were never close to fast enough to replace RAM, and the option to reboot in order to fix some weird state your system has gotten itself into is a feature of computers, not a problem to work around.
When the PDIMMs were used with an appropriate file system + kernel, it was pretty cool. NTFS + DAX + kernel support yielded a file system where mmap’ing didn’t page fault. No page faults because the file content is already there, instantly.
So if you had mmap heavy read/write workloads… you could do some pretty cool stuff.