World Community Grid - View Thread - BOINC: CPU Throttling using client or website preferences

Skipping forward to the 6.10 client version, herein a summary of features that are available from this release, points A-C as indicated in this screenshot of the BOINC Manager Advanced View Preferences (menu Advanced):

This is a new feature also referred to as the CPU usage monitor function and controls the percent at which the client should work, default 25%. If for instance a ceiling of 60% overall CPU system wide use is set and none-BOINC processes use anything less than 60%, BOINC will continue to use all remaining idle cycles it's allowed per point C. below. If the system/user percent exceeds this 60%, science applications are entirely stopped. A message is logged such as this:

Suspending computation - CPU usage is too high

A practical sample at an extreme low setting of 5%
```
suspend work if non-BOINC CPU load exceeds 5 %
(to change, visit the web site of an attached project,
or click on Preferences)
Suspending computation - CPU usage is too high
[cpu_sched] Preempting CMD2_0348-MYH3.clustersOccur-2QNK_A.clustersOccur_70_0 (left in memory)
[cpu_sched] Preempting CMD2_0349-MYH3.clustersOccur-2IP1_A.clustersOccur_341_844081_844739_0 (left in memory)
[cpu_sched] Preempting CMD2_0348-MYH3.clustersOccur-1M6B_A.clustersOccur_327_756284_756818_0 (left in memory)
[cpu_sched] Preempting CMD2_0349-MYH3.clustersOccur-2DAT_A.clustersOccur_94_0 (left in memory)
Resuming computation
```
It can take 20 seconds or longer before the process figures out what it's share should be, then constantly adjusting it's portion. Here the "Leave Application in memory when preempted" was selected. In case this is not, the tasks will unload from memory and resume from last checkpoint when the non-BOINC processor load drops below the set percentage.

This feature, as all other local preferences, overrides the website device profile settings.
This sets the number of processor threads that the client is allowed to use. On a single socket quad core computer it means:
- 49-25 percent, rounded down, 1 (25%) of the threads are used.
- 74-50 percent, rounded down, 2 (50%) of the threads are used.
- 99-75 percent, rounded down, 3 (75%) of the threads are used.
- 100 percent, all 4 threads/cores are used.
For a duo the logic is 99-50 percent, 1 core is used.
This is the ceiling of percent used by BOINC of overall CPU idle time. At the same 60% as used in point A., BOINC will use 60% of the spare time. If the system/user required use is higher than BOINC will use just whatever is left up to that 60% of total ceiling.

It only works if the Run based on preferences Activity menu entry is selected, else 100% is used of the idle system cycle time.

NB: The function point A is still under development, thus subject to functional change. The sample log was with the "Leave application in memory when suspended" on.