Just curious really. I had BOINC running on an old PC that died.

I presume the CP unit will eventually be sent to someone else. Will the calculations start again from the beginning or are my calculations saved with the trickle? Are part completed WUs sent out? Are incomplete units still valuable to the science. Should we endeavour to keep units running until completion? ie avoid resetting the project if we have problems?

Yes, the WU will likely eventually be sent to somewhere else.

Calculations will be started from the beginning. In order for another PC to resume where you left off, very very large files would need to be uploaded periodically during a run, then downloaded by whoever would resume it. This was not deemed feasible in terms of bandwidth and storage.

For the most part, incomplete WUs are not all that valuable to the project, but they are a fact of life in this DC project. Perhaps there might be something gained by the investigators on those runs that got through the 2nd phase but did not finish the 3rd, but that is speculation. It is best, if possible, to try to complete WUs, but errors and problems are sometimes inevitable so a reset is necessary.