Every unit counts, no matter how long it takes to process.

That's the fundamental idiom of distributed computing.

I have some really crappy old machines, but they still churn out WU's quite
handily, and my total overall would be significantly less without them.

3x DEC Alpha 650MHz running 64-bit Linux, hand-tuned, doing WU's very
quickly as 64-biut computing kicks 32-bit all over the place :)

1 Pentium-4 1800MHz that almost never gets a unit done because it's only on
when I am gaming or working, both of which hoard the CPU.

1 Pentium-3 1GHz laptop that never leaves the house much anymore, used
mainly for web searching and email, and of course crunching SETI WU's

1 Pentium 90MHz that does nothing but SETI WU's 24/7, and doesn't even have
a keyboard, mouse, monitor, etc.

1 Athlon 1100MHz that acts as a print server and crunches SETI units, also
no keyboard, mouse or monitor.