[Beowulf] Mersenne primes?

[Mark Reynolds]

I'm fairly new to Beowulfery but am reading TFM from
http://www.phy.duke.edu/~rgb/Beowulf/beowulf_book.php (great book by
the way). Does anyone know of any programs to find Mersenne primes
that are suited to parallelised environments such as a cluster made up
of nodes with multi-core processors? I've found mprimes from
http://www.mersenne.org/ but the FAQ states:
Although, a program could be written for dual-CPU systems (it would be
quite time-consuming), the machine will still get more throughput by
working on separate exponents.
Has anybody tried this and can Lucas-Lehmer testing be effectively
parallalised? Currently, you have to run an instance for each core for
it to get any benefit. Also I'd like to modify it so it could, for
example, search between certain numerical ranges independent of the
work units sent out through the website or to take advantage of 64-bit
hardware. Can someone more knowledgeable about this sort of thing tell
me  whether this is practical or if it has been done already?

Thanks.

-- 
"To win one hundred victories in one hundred battles is not the
highest skill. To subdue the enemy without fighting is the highest
skill."— Sun-Tzu