John wrote:

I am aware the SETI-BOINC software can make use of multiprocessor
machines. Can the software sense and make use of hyper threaded
virtual CPUs? For example - a dual HT enabled Xeon could run 4
instances at the same time!!

Yes it can. A friend of mine does that. Runs two WU's at the same time.
Saves about 10-15 min per WU too!

Mind you, you have to set your preferences right on the site.