long-2's not using only 5 threads when set to 6
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Message 7224 - Posted: 10 Jan 2021, 13:38:07 UTC

Noticed my machines were running cooler than expected and checked the process manager and saw the long2's are only using 5 threads for long periods. They can drop down to 2 threads and increase thread count but never seem to ever make it to 6.

They are set to:

<!-- srbase11 = Sierpinski / Riesel Base - long2 --> <app> <name>srbase11</name> <max_concurrent>1</max_concurrent> <fraction_done_exact/> </app> <app_version> <app_name>srbase11</app_name> <avg_ncpus>6</avg_ncpus> <cmdline>-t6</cmdline> </app_version>


Is optimal 4 threads or less to maximize CPU usage?

I ran over deadlines leaving these long2's at 1 or 2 threads.

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Message 7225 - Posted: 10 Jan 2021, 16:04:11 UTC - in response to Message 7224.

Noticed my machines were running cooler than expected and checked the process manager and saw the long2's are only using 5 threads for long periods. They can drop down to 2 threads and increase thread count but never seem to ever make it to 6.

They are set to:

<!-- srbase11 = Sierpinski / Riesel Base - long2 --> <app> <name>srbase11</name> <max_concurrent>1</max_concurrent> <fraction_done_exact/> </app> <app_version> <app_name>srbase11</app_name> <avg_ncpus>6</avg_ncpus> <cmdline>-t6</cmdline> </app_version>


Is optimal 4 threads or less to maximize CPU usage?

I ran over deadlines leaving these long2's at 1 or 2 threads.


Depends on how much CPU cache is used. On a ryzen 3950x there is a limit of 10 then it will be run slower.

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Message 7229 - Posted: 11 Jan 2021, 1:09:42 UTC - in response to Message 7225.
Last modified: 11 Jan 2021, 1:16:27 UTC



Depends on how much CPU cache is used. On a ryzen 3950x there is a limit of 10 then it will be run slower.


3950x has 64mb lvl 3 so we should set the thread count to use no more than about 6mb per thread?

My older server Xeons only have 20MB (still better than my 2700X GPU host) so will have to limit the number of long2 WU's.
1 WU at 3 threads per CPU; currently they are running 2 WU at 6 threads per CPU package. (there's probably a slowdown of all other project WU's as they compete for cache w/ the long2's)

Are all the WU's needing this amount of cache?

If you have some data about max cache per WU type; I'll put it into a spreadsheet chart.

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Message 7245 - Posted: 15 Jan 2021, 15:10:34 UTC
Last modified: 15 Jan 2021, 15:13:17 UTC

This is a management issue.

Resource share set to 0 on 16 core machine.
The project sends more longs than can be done in 1 day.
If I limit the long3 to 1 WU of 3 cores the project has sent 2, 3 or 4 WU and so 13 cores remain unused as the other connected projects are set to Resource share 0 and see a full work cache, so send no work. If I set one of those projects to resource share 1 then they dominate the work cache and SRBase sends no work.

I guess the only solution is to run SRBase within a 3 core VM's and put the rest of the workload in the main OS or other VM's.

BOINC's resource share system is terrible; designed when all computers were single core machines.
They need to add a work cache to each core, or group of cores, to give us more control over the workload.

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Message 7246 - Posted: 15 Jan 2021, 15:19:13 UTC - in response to Message 7245.

This is a management issue.

Resource share set to 0 on 16 core machine.
The project sends more longs than can be done in 1 day.
If I limit the long3 to 1 WU of 3 cores the project has sent 2, 3 or 4 WU and so 13 cores remain unused as the other connected projects are set to Resource share 0 and see a full work cache, so send no work. If I set one of those projects to resource share 1 then they dominate the work cache and SRBase sends no work.

I guess the only solution is to run SRBase within a 3 core VM's and put the rest of the workload in the main OS or other VM's.

BOINC's resource share system is terrible; designed when all computers were single core machines.
They need to add a work cache to each core, or group of cores, to give us more control over the workload.


Thats true. The work cache is also based on the GFLOPs.


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