SMP/dual (multi) core phase II

[Derek Atkins]

Daniel Feenberg <feenberg at nber.org> writes:

> We have tested quad core and dual core Intel core 2 duo processors doing 
> statistical calculations (long float arithmetic, mostly) and found the 
> quad core runs 4 independent processes at just about the same speed (each) 
> as 2 dual core processors of the same clock rate run them. So no advantage 
> seen to more sockets, only cores and clock rates count. None of the 
> processes is multi-threaded.
>
> Our little compute cluster ended up with 3 quad core motherboards and 1 
> double socket dual core. All 4 machines have nearly the same capacity. 
> This could be an artifact of floating point, we haven't tested other load 
> types.

Have you tested memory-intensive tasks and whether you get
more memory bandwidth in a quad-core or 2x dual-core?  Have
you compared Intel to AMD for memory throughput?   I don't
know your application so I don't know if it's memory bound or
CPU bound.

> Daniel Feenberg

-derek
-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
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