About Multi-cores and Multi-tasking

[Shlomi Fish]

Hi all!

I once read that in order to truly take advantage of having multiple cores on 
the same CPU, then one needs to use several threads. On the other hand some 
people assume or implied that if your application splits the work among 
several processes, then it can also take advantage of multiple cores. So my 
question is: can several distinct processes each execute in their own cores?

From my experience with benchmarking http://fc-solve.berlios.de/ , I've 
noticed that multi-processing was a bit faster than multi-threading on my 
P4-2.4GHz machine ("hyperthreading") while multi-threading was faster than 
multi-processing on my Intel x86-64-based laptop with two cores running in 
x86-64 mode. It's possible that the multi-tasking in both cases is sub-
optimal, but I've ran the same programs on both computers.

I'd appreciate if anyone can shed any light on it.

Regards,

	Shlomi Fish
-- 
-----------------------------------------------------------------
Shlomi Fish       http://www.shlomifish.org/
http://www.shlomifish.org/humour/ways_to_do_it.html

Deletionists delete Wikipedia articles that they consider lame.
Chuck Norris deletes deletionists whom he considers lame.

Please reply to list if it's a mailing list post - http://shlom.in/reply .