thank you for the answer.
Actually I already tried the solution in the linked thread some time ago: it does not work for cosmology@home on my system.
As soon as I have this vbox-app running, the performance goes down. I know that there was at least one core for a non-vbox app, but I need to check again if it is the same if no other vbox is running or not.
I know found out that there are other vbox apps which also cause performance issues on my system when running simultaneously to other vbox apps (even with at least 1 core left for anything else). Those performance issues are not nearly as bad as those from the cosmology vbox, and it seems to be only temporary while with cosmology it is all the time the vbox is running.
Then there are other vbox apps which do not cause performance issues at all, even when running simultaneously. So from my experience those performance issues are indeed app-dependent.
Does anyone know how to configure boinc to only run 1 vbox app at a time - across all projects? I can limit the instances per app/project, but that does not stop boinc from running a vbox from another project :)
thank you and best regards,