Re: Physical CPU? or multicore?

From: Greg Rahn <>
Date: Wed, 29 Apr 2009 10:33:39 -0700
Message-ID: <>

I think that many variables have been overlooked (or at least not mentioned) in this thread. The OP mentioned:

> But, from the performance perspective. Which is better?
> Having 8 physical CPUs? Or Having 1 Physical CPU with quad core and HT enabled?

In short the answer is "It depends". The long answer to this question is much bigger than the two options given. First, it depends on *what* you are comparing. Not too many CPUs are single core today so if you want to compare a 1P/1C (P=processor/socket C=core) CPU to a 1P/2C or 1P/4C processor you are either 1) comparing different CPU architectures or 2) comparing a recent CPU to an older one. When comparing old vs new there is much more to consider than cores or clock speed. The big factors that impact this include, but are not limited to 1) CPU cache (L1/L2/L3) sizes, 2) FSB/Northbridge speeds, 3) memory speeds. Any comparisons are also *very* application dependent, meaning that one can not generalize on performance as it depends on which resource was the bottleneck for that given application.

If you really want to dive into the new Intel Nehalem (which I may add is awesome!) I would suggest :

Greg Rahn
Received on Wed Apr 29 2009 - 12:33:39 CDT

Original text of this message