does Prime95 auto-save at shutdown?

[ixfd64]

OK, we know that Prime95 automatically saves every 30 minutes (by default) and when the user manually stops the program. However, does Prime95 auto-save when the user shuts down the computer? In other words, can Prime95 detect if a computer is shutting down?

If not, I should probably stop Prime95 manually before shutting down or restarting the computer. A loss of 30 minutes of work doesn't seem like much, but it all adds up.

[Uncwilly]

I can't see why George would not take this into consideration.
In my experience, it seems that Prime95 does do this.

Try it out for yourself.

[mdettweiler]

Originally Posted by ixfd64

OK, we know that Prime95 automatically saves every 30 minutes (by default) and when the user manually stops the program. However, does Prime95 auto-save when the user shuts down the computer? In other words, can Prime95 detect if a computer is shutting down?

If not, I should probably stop Prime95 manually before shutting down or restarting the computer. A loss of 30 minutes of work doesn't seem like much, but it all adds up.

I think it depends on whether or not the particular operating system it's being run on can send all programs a "signal" warning them to close before shutting down, or if it just shuts down without giving programs any warning. I know for a fact that Linux and most other Unixes do this; from what I can tell Windows may not do this most of the time, however. (It may depend on the application in question.)

I've always tried to shut down the various distributed-computing apps I've worked with manually before shutting down whenever possible--even on Linux where it's not absolutely necessary. Sometimes shutting down such an application manually, even if your operating system handles it on its own, can be beneficial in case the app needs just a little bit longer to save than the small window of time the OS gives it to shut down on its own after being warned of a shutdown. For example, I've seen Prime95/mprime take at least two or three seconds to save some large P-1 save files; similarly, a sieve program such as srsieve will take a while to save a relatively large sieve file.

As Uncwilly said--try it out for yourself, and get a feel for how long Prime95 takes to shut down wtih the types of save files you typically work with. You may also want to try, say, writing down the current % done on an LL test or whatever (assuming you have Prime95 set to update that somewhat frequently) before shutting down (without turning off Prime95 manually first), then when you start back up, compare the % done's. If the "new" percentage is slightly less than the "old" one, then your OS doesn't give Prime95 a chance to shut itself down properly before shutting down the computer.

[TimSorbet]

I've always noticed that Prime95 (or LLR) resume right where they were after I shut down (i.e. a planned shutdown, not a power outage...obviously ) on Windows XP. I'm pretty sure that Windows tells the programs to turn off in a nice way (i.e. doesn't just end them unexpectedly), but whether a program is made to properly save all work and close when that message comes across can vary, of course. I think that in trying to close programs during shut down, if it takes a few seconds longer than expected, it brings up the status indicator that lets you end the program immediately to let you shut down. This happens sometimes if, e.g. the explorer.exe process hangs and you try to log off or shut down, but I'd guess would also happen when ending Prime95/mprime on something it needs several seconds to save on.

[mdettweiler]

Originally Posted by Mini-Geek

I've always noticed that Prime95 (or LLR) resume right where they were after I shut down (i.e. a planned shutdown, not a power outage...obviously ) on Windows XP. I'm pretty sure that Windows tells the programs to turn off in a nice way (i.e. doesn't just end them unexpectedly), but whether a program is made to properly save all work and close when that message comes across can vary, of course. I think that in trying to close programs during shut down, if it takes a few seconds longer than expected, it brings up the status indicator that lets you end the program immediately to let you shut down. This happens sometimes if, e.g. the explorer.exe process hangs and you try to log off or shut down, but I'd guess would also happen when ending Prime95/mprime on something it needs several seconds to save on.

Yes, indeed--I forgot about the little status indicator thing. As you said, a lot of it depends on how the program responds to a shutdown signal--Prime95 and (manual) LLR tend to save while shutting down, whereas I've noticed that LLRnet (based on LLR, but much of the "surrounding" code is different) doesn't save before shutdown. (However, that's not to be confused with the Linux version of LLRnet, which shuts down properly and saves as it should.)

[mcduck]

Originally Posted by ixfd64

In other words, can Prime95 detect if a computer is shutting down?

Windows sends a signal to all applications upon shutdown (WM_QUERYENDSESSION) and will wait for applications to shutdown properly. Prime95 should save when this happens. If for any reason a application (Such as Prime95) does not shutdown within reasonable time there will be a warning displayed and you will be asked if you want to forcefully kill it (And loose all unsaved work). Did you not see this message, you can be pretty sure it shutdown as it should.

[Freightyard]

Originally Posted by mdettweiler

As Uncwilly said--try it out for yourself,... try, say, writing down the current % done on an LL test or whatever (assuming you have Prime95 set to update that somewhat frequently) before shutting down (without turning off Prime95 manually first), then when you start back up, compare the % done's.

Or, simply look at the "Date modified" time on the save files after power-up or reboot and see if it corresponds to the shut-down time.