RIP Optane/XPoint

By: Doug S (, July 30, 2022 10:43 pm
Room: Moderated Discussions
David Hess ( on July 30, 2022 3:44 pm wrote:
> David Hess ( on July 29, 2022 8:59 pm wrote:
> > Linus Torvalds ( on July 29, 2022 11:20 am wrote:
> > >
> > > You simply don't want a situation where all your memory is your long-term image. The whole "if
> > > you lose power, you reboot and just continue" thing is mindless blathering. Exactly because it
> > > makes a fundamental mistake in assuming that everything is always perfect and bug-free.
> >
> > I have developed small embedded systems which could do that with critical state stored in either EEPROM
> > or CMOS SRAM with backup power. Some old test instrumentation used battery backed up SRAM as main memory,
> > and would pick up exactly where it lost power, but I do not think that would be practical now at least
> > in that way. At the time, common CMOS SRAM was fast enough to be treated as main memory.
> >
> > It is not quite the same thing, but I have done some application programming where it was
> > convenient to keep state on mass storage which allowed the program to be modified and then
> > restarted without interrupting operation. This required an entire section of code for loading
> > external state at startup, and then continuously updating state as required.
> Last night I remembered another computer system which could start up exactly where it
> left off after power loss; this was a feature of some systems which used core memory.
> It was a small step from relying on core memory for program and data storage, to including
> circuits to safely shut down and restart after power loss by saving CPU state.
> This could also have been done with a microprocessor and CMOS SRAM or even DRAM, but
> I do not remember any systems which did it that way. Someone must have though.

This is before my time but in the core memory days booting was kind of a pain in the ass, was it not? Even if you had the luxury of a hard drive you probably had to either toggle in a bootloader or load it via paper tape.

That was probably the main reason that was used, not necessarily because they wanted to pick up where they left off - but if the PC, SP and registers were themselves stored in a type of core memory (or there was a big capacitor or something allowing a split second for them to be saved to core memory) then I guess theoretically it could simply pick up where it left off once power returns.
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TopicPosted ByDate
RIP Optane/XPointWes Felter2022/07/28 07:53 PM
  RIP Optane/XPointRayla2022/07/28 08:28 PM
  RIP Optane/XPointDoug S2022/07/28 09:00 PM
    RIP Optane/XPointNoSpammer2022/07/29 01:50 AM
    NVDIMM-NEric L2022/07/29 03:36 AM
    RIP Optane/XPointMichael S2022/07/29 04:02 AM
      RIP Optane/XPointDoug S2022/07/29 10:40 AM
        RIP Optane/XPointDoug S2022/07/29 10:43 AM
          RIP Optane/XPointLinus Torvalds2022/07/29 11:20 AM
            RIP Optane/XPointDavid Hess2022/07/29 08:59 PM
              RIP Optane/XPointDavid Hess2022/07/30 03:44 PM
                RIP Optane/XPointDoug S2022/07/30 10:43 PM
                  RIP Optane/XPointrwessel2022/07/31 05:33 AM
                  RIP Optane/XPointKonrad Schwarz2022/08/02 08:06 AM
                  RIP Optane/XPointDavid Hess2022/08/02 10:24 PM
                    RIP Optane/XPointDavid Hess2022/08/02 10:26 PM
                    RIP Optane/XPointAdrian2022/08/03 01:19 AM
        RIP Optane/XPointanonymou52022/07/29 12:50 PM
    RIP Optane/XPointGionatan Danti2022/07/29 09:09 AM
    RIP Optane/XPointMark Roulo2022/07/29 10:02 AM
      RIP Optane/XPointdmcq2022/07/30 03:42 AM
      RIP Optane/XPointanon32022/07/31 10:19 PM
        RIP Optane/XPointanon22022/07/31 10:55 PM
          RIP Optane/XPointDoug S2022/08/01 08:37 AM
            RIP Optane/XPointGionatan Danti2022/08/01 01:33 PM
              RIP Optane/XPointNoSpammer2022/08/02 03:50 AM
                RIP Optane/XPointDoug S2022/08/02 09:24 AM
                  RIP Optane/XPointGionatan Danti2022/08/02 10:34 AM
                  RIP Optane/XPoint---2022/08/02 10:39 AM
            RIP Optane/XPointDavid Hess2022/08/03 03:48 AM
              RIP Optane/XPointMichael S2022/08/03 06:04 AM
                RIP Optane/XPointDavid Hess2022/08/03 08:56 AM
        RIP Optane/XPointAdrian2022/08/01 02:15 AM
          RIP Optane/XPointGionatan Danti2022/08/01 06:07 AM
            Losses vs not profitable enoughMark Roulo2022/08/01 10:15 AM
              Losses vs not profitable enoughdmcq2022/08/01 11:50 AM
                Losses vs not profitable enoughGionatan Danti2022/08/01 12:34 PM
            RIP Optane/XPointMichael S2022/08/01 02:47 PM
              RIP Optane/XPointAnon2022/08/01 03:09 PM
                RIP Optane/XPointMichael S2022/08/01 03:32 PM
      RIP Optane/XPointGroo2022/08/01 12:28 PM
        RIP Optane/XPointanon32022/08/01 10:33 PM
          RIP Optane/XPointGroo2022/08/03 11:15 AM
            RIP Optane/XPoint---2022/08/03 03:05 PM
    LatencyDavid Kanter2022/07/29 06:35 PM
  Operating system and driver overheadEric L2022/07/29 03:44 AM
    Operating system and driver overheadLinus Torvalds2022/07/29 10:45 AM
  altrernatives?Michael S2022/07/29 05:17 AM
    altrernatives?Rayla2022/07/29 06:49 AM
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