Michael S (already5chosen.delete@this.yahoo.com) on July 29, 2022 4:02 am wrote:
> 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".


I've seen about a half dozen datacenters lose power over my years consulting for various Fortune 500 companies. All had UPS, either the UPS failed, the transfer to generator failed, or the generator failed or ran out of fuel after starting.

In addition to those site specific issues you also have cases like the power outage in 2003 where if you didn't have enough diesel fuel on site to last several days you were screwed because you couldn't get more.

A UPS is not sufficient. I am assuming the market for Optane DIMMs was servers in a datacenter that have data of value to a business that is too costly to lose. No one was installing them on a home PC, let alone a laptop.