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Fold when idle?

Posted: Tue Apr 28, 2009 9:09 am
by Coldplayer
Wondering if F@H is ever gonna have a feature where it'll stop folding when the comp is doing something else resource heavy or only start when comp is idle.

Thanks

Re: Fold when idle?

Posted: Tue Apr 28, 2009 9:52 am
by P5-133XL
It already does that. The way Windows works is that it has a priority system set up such that Windows always does activities that are higher in priority before doing anything of lower priority. Folding has a very low priority, effectively just slightly above idle. So Folding only replaces idling and if anything else of higher priority wants to run (virtually everything) then it gets the entire use of the CPU: folding simply will not run until the computer is idling again. So folding only uses the surplus CPU cycles and does not really interfere with other uses.

Re: Fold when idle?

Posted: Tue Apr 28, 2009 12:11 pm
by bruce
Coldplayer does have a point -- and so does P5-133XL.

Because Operating Systems have years of development behind them, they have a very sophisticated task scheduler which can make very good decisions about which task to run next. Coldplayer's resource heavy task will suspend the FAH automatically specifically because FAH has been set up to use an extremely low priority. This works extremely well for the standard uniprocessor version except in systems which have very small amounts of RAM. It works almost as well for the SMP version, but it's still under development and it is officially a "high performance client" which means you have been warned that it may have an impact on other tasks (slowing them down). Unfortunately, at this stage of development, the SMP version has bugs which prevent configuring it so that it stops folding frequently.

At one time, FAH had a true Windows screensaver version, but it was discontinued because stopping folding and restarting is something that must be done rarely, and as a general rule, screensavers are suspended rather frequently. FAH is designed to run continuously and there's a big difference between suspending a task while something else runs and stopping that task and restarting it later. The FAH developers continue to struggle with the virtual impossibility of reconciling those two concepts.

It might be possible to configure the GPU client to start when the system is idle and stop when it is no longer idle. I don't believe it has been tested to see how much work is lost if it is set up to stop/start frequently. It might work and it might not. Does anybody want to test it? I believe a scheduled task can be configured to run anything only when the machine is idle. Try it and let us know if you run into any problems which are different that the problems already being reported for the newest version in it's current state of development.

Re: Fold when idle?

Posted: Sat Jan 30, 2010 4:33 pm
by Psimon
bruce wrote: At one time, FAH had a true Windows screensaver version, but it was discontinued because stopping folding and restarting is something that must be done rarely, and as a general rule, screensavers are suspended rather frequently. FAH is designed to run continuously and there's a big difference between suspending a task while something else runs and stopping that task and restarting it later. The FAH developers continue to struggle with the virtual impossibility of reconciling those two concepts.
I'm new to Folding@Home, so if this is a dumb idea apologies in advance ;) .

I too was hoping for a Folding@Home screensaver version (I got the latest version which is 6.23).

Instead of starting and stopping folding dependent on the screensaver, why not simply display the work being done when a screensaver becomes active? What I mean is, when you select "Display" from one of the FAH clients (I'm running both the CPU and GPU versions) by rightclicking on it in the tray, it brings up that window showing the molecule rotating, and work being done, etc. Is there any way to create a screensaver that does the same? So it doesn't affect the work in progress, just displays it.

Re: Fold when idle?

Posted: Sat Jan 30, 2010 6:54 pm
by jrweiss
The FAH_GPU_IDLE Environment Variable for the ATI GPU client works well to reduce screen lag that is noticeable in several common scenarios. With it set to 5, the browser scroll delays I used to see have been largely eliminated.

Reducing the CPU load to 95 or 98% in the CPU or SMP clients will usually give enough "headroom" so an app can grab enough CPU time while F@H is releasing them, also eliminating perceivable delays. You may need as low as 85% for an old, slow machine (P3). As Bruce mentioned, low RAM will cause delays as the pagefile is written to disk.

As for screensavers, I believe they are largely falling out of favor, since CRT burn-in is not much of an issue any more, and monitor Suspend or Sleep modes are more often used to save electricity. I wouldn't spend a lot of time on screensaver interfaces...

Re: Fold when idle?

Posted: Sat Jan 30, 2010 7:09 pm
by toTOW
jrweiss wrote:The FAH_GPU_IDLE Environment Variable for the ATI GPU client works well to reduce screen lag that is noticeable in several common scenarios.
This is a nVidia variable, not ATI.

Re: Fold when idle?

Posted: Sun Jan 31, 2010 3:38 am
by jrweiss
Hmmm... Someone recommended it a while back for Core 11 in general: viewtopic.php?f=50&t=11978&hilit=+FAH_GPU_IDLE+

It doesn't do anything bad, and it APPEARS to do good with ATI. Maybe it was the OS and Cat upgrades...

Re: Fold when idle?

Posted: Sun Jan 31, 2010 1:57 pm
by toTOW
It will simply be ignored by ATI cores ... so it can't hurt, but it's useless.

Re: Fold when idle?

Posted: Fri Sep 21, 2012 10:03 am
by Aleksey314
A question. Is there any way to set FAHControl (CPU type) so that it suspended any of its work when a specific other application is in use (namely BOINC client). If they are running simultaneously, they seem to share the CPU resources. And I want FAHControl work only when BOINC is idle, waiting for its WU to come or loading them. Thank you in advance.

Re: Fold when idle?

Posted: Fri Sep 21, 2012 1:15 pm
by 7im
No suspending. This is by design because unlike work from other projects which are not time sensitive, FAH work units are time sensitive. Generation B work unit cannot be processed until Gen A work unit is completed. Each builds on the next.

Re: Fold when idle?

Posted: Fri Sep 21, 2012 3:04 pm
by Jesse_V
See https://fah-web.stanford.edu/projects/F ... /ticket/83
But yes, Folding@home's Work Units need to be completed in a timely manner, which is why they have bonus points awarding quick returns, and also why the units have deadlines. Still, there are some good reasons to pause processing.

Re: Fold when idle?

Posted: Fri Sep 21, 2012 4:10 pm
by bruce
Aleksey314 wrote:A question. Is there any way to set FAHControl (CPU type) so that it suspended any of its work when a specific other application is in use (namely BOINC client). If they are running simultaneously, they seem to share the CPU resources. And I want FAHControl work only when BOINC is idle, waiting for its WU to come or loading them. Thank you in advance.
Welcome to the foldingforum, Aleksey314.

If you only run FAH when BOINC is waiting for a new WU to download, FAH won't get enough resources to complete a WU within its deadline and you're efforts to run FAH will be useless. Perhaps you don't appreciate how time-sensitive FAH actually is.

In the past, I've recommended that if people want to share resources between FAH and BOINC, that they run FAH exclusively for N days, making sure to complete any WU that has been assigned and then run BOINC for M days, making sure to complete any WU that has been assigned. (Since most BOINC projects have deadlines but are not all that time-critical, you may not need to complete the WU that has been assigned since it can be finished N days later, but it is really important not to leave a FAH WU to be completed M days later.)

If that doesn't work for you, (assuming you're planning to run FAH SMP) allocate a certain number of your CPU-cores to BOINC and the remainder to FAH. Be sure to set FAH priority to "low" so it gets a fair share if there's any contention.

If neither of those work for you, decide which project you wish to support and run it exclusively (even if that's not FAH). Returning completed FAH WUs late is worse that not folding at all.

Re: Fold when idle?

Posted: Thu May 28, 2020 12:12 am
by Toredon
If I put it on only when idle, it never starts folding, just stays waiting for idle.

Re: Fold when idle?

Posted: Thu May 28, 2020 3:51 am
by JimboPalmer
Toredon wrote:If I put it on only when idle, it never starts folding, just stays waiting for idle.
Welcome to Folding@Home!

You have reopened an 11 year old thread which has not had a post in 8 years. Almost all the 'facts' in it are currently wrong, some of the posters are deceased.

"Idle" is defined by the OS, not F@H. In Windows, when screen goes blank or to a screensaver, it is idle. On a Mac, there is a timer when no keyboard or mouse activity that defines idle. i do not understand the rules in Linux, I suspect they vary by Window Manager.

Since I don't know which you use, I can't comment further.

Re: Fold when idle?

Posted: Thu May 28, 2020 9:16 am
by PantherX
Welcome to the F@H Forum Toredon,

Can you please post the log file? Ensure you include the first 100 lines which will inform us of what the system configuration is and what the client settings are. If you require guidance, please view this topic: viewtopic.php?f=24&t=26036