Writing to disk intervals

Jim Milks
Jim Milks
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Topic 192094

Just wondering if increasing the interval time for the "Write to Disk at most ___ seconds" in the preferences will do anything to my crunch time (my MacBook normally takes ~22,000 sec per long WU). The default is 60 seconds. I'd like to try 120 seconds if that would make any difference in crunch times. Anyone have any experiences (good or bad) with changing the default write to disk interval?

Thanks.

Keck_Komputers
Keck_Komputers
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Writing to disk intervals

It usually doesn't make much difference. However the actual effect depends on the science app and the disk drive. I personally have mine set at 300 seconds (5 minutes) that seems a reasonable balance between frequent backups and overworking the disk drive to me.

BOINC WIKI

BOINCing since 2002/12/8

Nothing But Idle Time
Nothing But Idl...
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I can't add much of

I can't add much of significance except this...

If BOINC or your computer needs restarting, how comfortable are you with going back to the last checkpoint and re-running 1 minute, or 5 minutes, or 10 minutes of the task?

As KK said, no need to wear out your disk either.

I personally use 5 minutes but I do something that maybe others don't: I get frequent updates to my computer that often require a re-boot afterwards to become effective. So I monitor the Einstein task in the slots directory and when I see a check point written I suspend the task and re-boot. Then the task restarts where it left off without going back 5 minutes.

Dimmerjas
Dimmerjas
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To try an speed up

To try an speed up performence, you could try this:

1)
Anything that moves, shown on a screen, is a CPU-consumer.
Don't use any kind of Screensaver. Or show project's grafics. Don't have the BOINC Manager shown on the screen.
Hide the BOINC Manager. Turn off the screen, after not using the computer for X minutes. When it is idle.
I let my hosts go into a black screen after idle of 3 min.

2)
If you can, disable the CD Rom drive(s). The CPU is using a lot of time checking, if you have inserted a CD, that must be started automatically. You can enabel the CD Rom drive(s) again, when needed.
I tried this during SETI Classic on a 1000 MHz computer. It made the computer 2.5% faster.

I don't think, that changing the time between writing to disk, may have much influence on the performence. It's more, like Ken Komputer say, to spare the disk drive.

Lord_Vader
Lord_Vader
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I put mine at "999" seconds.

I put mine at "999" seconds. I would do more, but BAM won't take it. I was trying more on the extreme power saving side. I went through all of my PCs and made sure I have enough RAM for the project they were crunching for and jacked the preferences way up. Once everything settled in, I went from 605 to 615 watts down to 575 / 580. Not much, but it was interesting to see what a few config changes could do.

Fear will keep the local systems in line. Fear of this battle station. - Grand Moff Tarkin

Alinator
Alinator
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Agreed, it's interesting to

Agreed, it's interesting to play with the prefs and see what effects it has on your hosts. :-)

However, for "Write to Disk", you really should be careful when upping it to hours if you're doing it for a slow host. You could end up having to repeat the whole calculation on a mostly completed result if something "bad" happens (discovered by sad personal experience). ;-)

As always, common sense should play a large role when setting prefs.

Alinator

Lord_Vader
Lord_Vader
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RE: Agreed, it's

Message 52891 in response to message 52890

Quote:

Agreed, it's interesting to play with the prefs and see what effects it has on your hosts. :-)

However, for "Write to Disk", you really should be careful when upping it to hours if you're doing it for a slow host. You could end up having to repeat the whole calculation on a mostly completed result if something "bad" happens (discovered by sad personal experience). ;-)

As always, common sense should play a large role when setting prefs.

Alinator

Yes, I agree.

I am working on a diskless farm to see if I can squeeze a few more watts out of it. I try to not exceed 650 / 700 watts or so with the whole farm and if I get down enough, I have a couple more hosts to light up. :-)

Fear will keep the local systems in line. Fear of this battle station. - Grand Moff Tarkin

Jim Milks
Jim Milks
Joined: 19 Jun 06
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The consensus seems to be

The consensus seems to be changing the write to disk interval will spare the HD but have little to no effect on crunch times. I'd already turned the screensaver off two months ago (disabling the screensaver decreased crunch times on my slowest computer by about 9% and on my fastest computer by about 2-3%).

Thanks to all who wrote. I've changed my write to disk interval to 5 minutes to give my HD a break. Happy crunching.

Joachim Schmidt
Joachim Schmidt
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RE: The consensus seems to

Message 52893 in response to message 52892

Quote:

The consensus seems to be changing the write to disk interval will spare the HD but have little to no effect on crunch times. I'd already turned the screensaver off two months ago (disabling the screensaver decreased crunch times on my slowest computer by about 9% and on my fastest computer by about 2-3%).

Thanks to all who wrote. I've changed my write to disk interval to 5 minutes to give my HD a break. Happy crunching.

Hiho,
you could also install a ramdisk, and install einstein on this. So your hard drive could go to sleep and won't crash faster.
I did this on my server which runs 24/7 and have no problems.

greets

Dex
Dex
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From my experience, when I

From my experience, when I was somewhat unaware of the exact results of changing my Write-To-Disk Interval. I changed it to .001 I believe.
After about 12 hours, my computer slowed, was sluggish, and the harddrive seemed to have a cache IO problem. Of course this was a VERY SMALL value to set for my WTD interval. But, even with a interval of 60 seconds, after a few weeks of running on a computer without restarting BOINC or rebooting the sytem, could cause similar results, but only take longer to reach those results. I currently have my WTD Interval set to 3600 seconds. Seems to be working fine. But, if you Shut-down and restart your computer frequently, it is advisable to set your WTD Interval to 60 seconds, so minimal data computations are lost.

d3xt3r.net

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