And NO software changes
I've worked extensively with NVRAM architectures. Any of the byte-addressable tape open Pandora's box on software changes (all for the better, I might add).
Just using it as RAMDisk doesn't cut it. The OS virtual file system and SCSI stack are too clunky to even try, and they don't provide granularity or atomicity. Moreover, apps need to understand the NV nature of NVRAM memory to take advantage of it. That means compiler and link editor changes galore.
Then there's the issue of data integrity and a minimum of RAID.
There's a lot more, but you get the point!