Not sure of the limitations of screensavers, so this might not be possible, but it would be nice if the screensaver could start BOINC running if BOINC is not already running.

I run BOINC on a home PC, and will sometimes need a touch of extra performance for gaming, and so will turn BOINC off. It would be nice if the screensaver could turn BOINC back on by itself instead of just complaining that it's not running.

It's probably not possible; I don't know if I'd be comfortable allowing a screensaver that much potiential control over my PC, but it would be nice if it could be done.

This idea already exists as exclusive_app in Client configuration, which is implemented in cc_config.xml, described here.

cc_config.xml has to be created by users.
Some examples of exclusive_app are described here

As far as I know, since BOINC 6.4, the screen saver does start the client. How long have you waited? Did you also set that BOINC should only do work when the computer is idle? What kind of videocard do you have? Is it really a card, or an embedded chip? Are you crunching CUDA on any project?

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