Intel Dual Core Performance Preview Part I: First Encounter

The Intangible Dual Core

The move to dual core is a bit of a "catch 22". In order to deal with the fact that a dual core die is twice the size of a single core die, AMD and Intel have to use higher yielding transistors.  The larger your die, the more defects you have; so, you use higher yielding transistors to balance things out.  The problem is that the highest yielding transistors run at the lowest clock speeds, so dual core chips end up running at slower speeds than single core chips.  While the Pentium 4 could have hit 4GHz last year, we won't break the 4GHz barrier until late 2006 at the earliest. 

In Intel's case, we're talking about 2.8GHz - 3.0GHz vs. 3.6GHz - 3.8GHz for the high end single core chips.  In order to offset the difference, Intel is pricing their dual core chips within about $80 of their single core counterparts.  Short of giving dual and single core chips a price parity, this is by far the best approach to assuring dual core adoption. 

Why does Intel want to encourage dual core adoption?  To guarantee a large installed user base, of course.  The problem today is that the vast majority of desktop systems are single processor systems, meaning that most developers code applications for single processor systems.  To encourage a mass migration to develop multithreaded applications, the installed user base has to be there to justify spending the added time and resources in developing such applications.  As we just finished mentioning, Intel's approach is the quickest way to ensure that the exodus takes place.

So, with dual core CPUs priced very close to their single core counterparts, the choice is simple right? 

On the Intel side of things, you're basically giving up 200MHz to have a dual core processor at virtually the same price.  But things get a lot more complicated when you bring AMD into the situation.  AMD hasn't officially released their dual core availability and pricing strategy, but let's just say that given AMD's manufacturing capacity, their dual core offerings won't be as price competitive as Intel's.  Now, the decision is no longer that simple; you can either get a lower clocked dual core CPU, or a higher clocked single core AMD CPU for the same price - which one would you choose? 

The vast majority of desktop application benchmarks will show the single core AMD CPU as a better buy than the dual core Intel CPU.  Why?  Because the vast majority of desktop applications are single threaded and thus, will gain no benefit from running on a dual core processor. 

Generally speaking, the following types of applications are multi-threaded:

• Video Encoding
• 3D Rendering
• Photo/Video Editing
• most types of "professional" workstation applications

However, the vast majority of other applications are single threaded (or offer no performance gain from dual core processors):

• office suites
• web browsers
• email clients
• media players
• games, etc.

If you spend any of your time working with the first group of applications, then generally speaking, you'll want to go with the dual core CPU.  For the rest of you, a faster single core CPU will be the better individual performance pick.

But once again, things get more complicated.  Individually, single threaded applications will make no use of a CPU able to execute multiple threads.  But, run more than one of these applications at the same time and all of the sudden, you're potentially dispatching multiple threads to your processor and thus, potentially, have a need for a multi-core CPU.