Doug S (foo.delete@this.bar.bar) on July 28, 2022 9:00 pm wrote:
>
> The only real advantage it had was as "byte addressable flash" when used in a DIMM form factor,
> but that's really of limited utility. Most people have no desire for their RAM to be unchanged
> when they reboot their system, they just want RAM that's protected against power loss.
>
> It seems odd to me there isn't (as far as I know?) a market for DIMMs with an integrated battery
> that can perform refreshes to cover power loss. You only need it for as long as is required to
> regain power and reboot the systems. There isn't any need for DIMMs that will maintain their state
> for months without power like Optane was capable of. Yes battery backed DIMMs will cost more per
> bit, but it will be at full DRAM performance rather than more like flash performance, so while
> it isn't the same thing it is close enough for those who have a need for non volatile RAM.

Good Old UPS works better for 99% of those who don't already have UPS in form of laptop battery.
And for 99% of remaining 1%, some form of "local mini-UPS" either on board or within system power supply works better than "micro-UPS on every DIMM".