So when you're talking about dual cores and their applicability to
multi-threaded software, if the computer is going to be "single tasked"
(i.e. left almost 24/7 solving a single problem with a single program)
you're best off with a single core CPU?

So the only time a dual core would be worth it for a single task would
be if it offers a much cheaper alternative to single cores on a
cost/FLOP basis?