hello community, beside having Boinc running on 2 PCs with dual core processors (where 2 tasks are being executed simultaniously), I recently have installed Boing on a PC with an Intel Pentium 4 (3GHz) processor, which has 1 core but 2 threads (and in the device manager is actually being shown a 2 processors). However, only 1 BOINC task is being executed at a time, using up only slightly below 50% of the processor. Nowhere in the BOINC Manager 7.2.47 I could find a setting in which I could tell BOINC to use both processor threads, hence using up to 100% of the processor's capacity; in fact, I am not using this PC for anything else than BOINC.
Any advice for me?

Too many variables; please help narrow the problem down:

1. Look at Tools-->Computing Preferences-->Processor Usage tab. What does it say near the bottom after "On multiprocessor systems, use at most _____%..."? Remember, BOINC generally treats hyperthreads transparently as CPUs (I think you can get clever in the back-end settings and distinguish physical from virtual CPUs, but that's for later discussion.)

2. Are you using a web-based account manager like BAM? There might be a discrepancy between your local preferences and web-based settings.

3. Are you running a project that uses multiple threads for one task? (e.g., Milkyway@Home) Look at the running task and see if the application name has "(mt)" at the end. Those tasks will only show up as a single running task while actually using all available cores/CPUs.

4. There could be other combinations of settings that might be forcing BOINC to throttle back based on your system load.

There are other possibilities that a more knowledgeable person can help you tease out, but I thought I'd try to make a rough stab at it first so that the resident experts can take a breather.

Too many variables; please help narrow the problem down:

1. Look at Tools-->Computing Preferences-->Processor Usage tab. What does it say near the bottom after "On multiprocessor systems, use at most _____%..."? Remember, BOINC generally treats hyperthreads transparently as CPUs ...

Based on your posting, once more I fiddled around with the Processor Usage settings.
It said "On multiprocessor systems, use at most 80% of the processors". I raised this to 90% - no change. 99% - no change. Only at 100%, the second thread started working. That's interesting, but it works this way.
More fine-tuning I can do with the tab "use ... % of the processor time" - I set this to 80%, in order not to have the processor work full load permanently - and it works. The processor temperature goes down a little bit (behaviour desired by me), but still both threads are active.
So, all is working out well now :-) You made my day !

It said "On multiprocessor systems, use at most 80% of the processors". I raised this to 90% - no change. 99% - no change. Only at 100%, the second thread started working. That's interesting, but it works this way.

This value is an integer, meaning that in the case of a 2 core CPU, you can only set 1 or two cores (or threads). 0-49% means no cores, 50-99% means 1 core and 100% means 2 cores.

On a 4 core CPU, that's 0-24%, 25-49%, 50-74%, 75-99% and 100% for 0,1,2,3,4 cores.

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More fine-tuning I can do with the tab "use ... % of the processor time" - I set this to 80%, in order not to have the processor work full load permanently - and it works. The processor temperature goes down a little bit (behaviour desired by me), but still both threads are active.

You could also use the third-party app, Tthrottle, to adjust your BOINC load on the fly to maintain a certain maximum CPU temperature. However, you would have to test it to see if the onboard temperature sensor in your older CPU would be recognized/compatible with the software.

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