Sorry if this is a dumb question, but may I ask what is the logic of requesting new tasks for cache like behind "Store at least X days of work" v.s. "Store up to an additional X days of work" in the BOINC client computing preferences configuration?

say what would the difference of the following two configurations be?

"Store at least Y days of work" and "Store up to an additional Z days of work"

"Store at least Y+Z days of work" and "Store up to an additional 0 days of work"

How would BOINC decide whether it will cache the MAX number of tasks and when not to?

Thanks!

If BOINC has less than "Store at least X days of work" available, for a given resource, then it starts asking projects for work for that resource.

When asking a project for work for a given resource, it will ask for enough work that will keep the computer busy not just for that "Store at least X days of work" setting, but additionally for "Store up to an additional X days of work".

More info can be found here:
http://boinc.berkeley.edu/trac/wiki/GpuWorkFetch
http://boinc.berkeley.edu/trac/wiki/ClientSched
http://boinc.berkeley.edu/trac/wiki/ClientSchedOld