1) Message boards : CMS Application : Had ~100 failures on CMS 50 (Message 43275)
Posted 24 Aug 2020 by far
Thanks, that helps understand the restricted usage of available resources. Wish I could have afforded 64GB of RAM.

However all the CMS50 tasks were failing anyway :-(

If there are logs or anything that is needed to check why please let me know. In case it's a factor, the version of VirtualBox is more recent than the one distributed with Boinc being 6.1.12r139181 (Qt5.6.2)
2) Message boards : CMS Application : Had ~100 failures on CMS 50 (Message 43262)
Posted 24 Aug 2020 by far
Hi Team,
Noticed that a machine wasn't using all of it's CPU power and tracked back to something with the CMS tasks.
They have been failing for a while but also preventing other tasks from utilising the PC's resources properly:
I've disabled CMS so other projects can ramp the PC up to 100% CPU again, but would be great if you can spot anything up with it so I can re-enable it.
The machine had lots or resources free but for some reason this project was preventing them being used.
Eg 32 threads but BOINC put other projects in a "Waiting for memory" state when there was heaps free, plus was only seeing ~32% of CPU being used.

If there are logs or any assistance I can provide please let me know,
Thanks, Far
3) Message boards : Number crunching : Inefficient usage of AMD threadripper 16c32t CPU (Message 40422)
Posted 13 Nov 2019 by far
Updating VirtualBox to current version (not the old one bundled by Boinc), plus disabling Atlas and theory tasks got the machine running at about 95% consistently (albeit over a spread of tasks). Which was quite an improvement over the previous average but about the same peak/best usage.

After applying Windows 10 feature update 19H2 today, the pc sits finally sits consistently at 100% usage! After nearly 2 years..
There was something in the update about being more aware of cores and tasks + favoured cores etc, and it's made a difference for me :-)

Hopefully this helps others with same issues also.
4) Message boards : Number crunching : Inefficient usage of AMD threadripper 16c32t CPU (Message 40248)
Posted 23 Oct 2019 by far
Hi there
VirtualBox is now upgraded to current. Hopefully this makes it more understanding of the AMD architecture and ways to group CPUs efficiently.
The Boinc group had recommended not to upgrade, but as you are the only project on that machine using it, it is all good.
To stop idle time on this machine which was basically built just for boinc, I've disabled Atlas and theory tasks -> hopefully it will run as close to 100% as possible for most of the time now.
If there are better setting of preferences, eg limiting the number of CPUs available for LHC tasks instead - please let me know
Thanks and regards, Far
5) Message boards : Number crunching : Inefficient usage of AMD threadripper 16c32t CPU (Message 40172)
Posted 16 Oct 2019 by far
There appears to be extremely inefficient usage of an AMD threadripper CPU with LHC projects.
Currently a 32cpu theory simulation 263.98 job is running. While it locks out all 32threads, it only uses 18% of the CPU capacity.
Other LHC jobs perform in a similar manner, even when they are 8CPU jobs. eg Atlas tasks will also cause the same sort of issue.

All other CPU based BOINC projects running which use individual threads for a task will use 95-98% of the CPU capability consistently.

The AMD CPU has chiplets - small groupings of CPUs (8 from memory) which are on different bits of silicon and connected via a substrate under the CPU cover.

Q1 - Would it cause any issues if I upgraded the virtual box installation to whatever is current? From it's release notes the more recent versions would appear to be more aware of what quirks the AMD CPUs may have as compared to the Intel ones and maybe this could assist.

Q2 - Is there any advice which regarding preference settings which could assist in more fully using the CPU?

Thanks, Far

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