It simply does not work. The application will crash and get frozen if you have more than 8 threads. Fortunately, we can fix it, well, sort of.
First, we must go to the boinc folder. In windows systems it is C:\ProgramData\BOINC\ , in linux systems most users will have it installed in /var/lib/boinc .
Once there we enter the projects folder, and then, the www.cosmologyathome.org folder. And we create a file named app_config.xml . In windows, make sure you are using the UTF-8 enconding, and not the ANSI one and copy and paste this :
<app_config>
<app>
<name>camb_boinc2docker</name>
<max_concurrent>1</max_concurrent>
</app>
<app_version>
<app_name>camb_boinc2docker</app_name>
<plan_class>vbox64_mt</plan_class>
<avg_ncpus>8</avg_ncpus>
</app_version>
</app_config>
It will lock the project to a maximum of 8 cores, case we want to lock it to less, we just have to change that number 8 for a smaller number.
I found this answer originally in the boinc forums, but i have not managed to find the original post again.
Thanks for the advice, I am only crunching Cosmology on a PC without VitrualBox so I haven't run into this problem but I will bookmark this article for future reference.
I have used app_config.xml to restrict memory hungry projects on my low spec computers but this is a much more detailed fix than I would have created on my own.
I have created ANSI encoded (default encoding for Notepad) app_config.xml files on Windows without any problems but it's also advice I will keep on file in case the encoding does ever cause issues for me.
Fellow BOINC hackers can find general information about the use of app_info.xml at https://boinc.berkeley.edu/wiki/Client_configuration
thats not hacking its pretty well known you can create and edit app xml files , you can even run multiple threads on GPU's , that too is not hacking its called configuring your setup.
I meant hacker as in a computer operator using some ingenuity to overcome a problem. Since the use of app_config.xml requires knowledge of the BOINC system beyond its everyday use I consider it a basic hack.
I was using the word hacker as way of creating a distinction between users who are willing to take extra steps to optimize their systems and users who prefer automatically configured settings or GUI based configuration tools.
Some definitions of Hacker:
https://en.wikipedia.org/wiki/Hacker (definition 1)
http://www.catb.org/jargon/html/meaning-of-hack.html
https://en.oxforddictionaries.com/definition/hacker (definition 1.1)
I did not intend to imply malicious or unauthorized activity.
Hacking depends a lot on context . Manipulating images used to be called hacking too. Its one of the most peculiar examples of language evolution.