It seems that the way BOINC handles CPU throttling has confused many, and at least one user has called into question the exact verbiage of "Use at most" X% of CPU time, thinking that it should never go over X%.

I suggest changing the verbiage to "Use on average" X% of CPU time. This may clear up at least some misunderstanding as to how BOINC throttles CPU usage as an average and not an absolute.

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Could the explanations contained in the forums re %of CPU Time be condensed into a short document and a link be included in the preferences page?

A percentage of new users like me will always be confused, no matter how it is worded.
CPU Usage Percentage. Thanks Ozzfan for the link in your signature.

Andrew :)

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AndrewM

The whole thing is a misnomer anyway as you're not throttling a percentage of the CPU time, but throttling BOINC.

When BOINC is using the CPU, it'll do so at maximum CPU cycles. Whether you use throttling or not. All the throttling does is suspend the application for so many seconds every 10 seconds, depending on the percentage you set.

You're not throttling the CPU time, as any task that takes 40 CPU minutes will still take 40 CPU minutes when run with 50% throttling. That the wall time will be anywhere from 40 to 80 minutes (or more) doesn't matter.

But come up with a good description and I'll add it to Trac.

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The whole thing is a misnomer anyway as you're not throttling a percentage of the CPU time, but throttling BOINC.

I fully agree, but if you read thread [url=http://setiathome.berkeley.edu/forum_thread.php?id=44698]"Please, Can BOINC/SETI CPU Utilization Be Made Smoother?" over in Number Crunching, user Brenda (who obviously has two different issues going on) seems to think her problem is the throttling that is causing poor performance, and it's the verbiage in the preferences that seems to have led her to this incorrect idea.

So I thought it might be a good idea to change the wording so others won't come to the same incorrect conclusion.

But come up with a good description and I'll add it to Trac.

The only thing I can come up with is changing a single word, from "Use at most" to "Use on average" so that people know it's not an absolute (i.e. BOINC will only use 50% and no more) but more of an average (BOINC will use on average 50% of your CPU).

Just a minor change, but it may go a long way toward preventing further confusion.

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FWIW it would make the most sense to me if the whole thing were to be inverted:

“Reduce CPU usage by: [default=0] percent
Enforced by version 5.6+
(Pauses processing every few seconds to improve cooling in portable or compact computers.)”

Something like that, anyway. I imagine the preference form could easily convert the percentage back to the usual format (and vice versa when displaying the current setting) so as to avoid having to make changes to the implementation in the CC.

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Odysseus' suggestion works well too.

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OK, I'll go with Odysseus' description.

Do know, that the 5.10.38 we're now testing has the new throttling option built in, which does work with 1/10th of a second throttling. Or at least, we should test that. ;-)

ticket [trac]#542[/trac].

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