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.

The Platform: Intel 955X Scheduling and Responsiveness


View All Comments

  • Da DvD - Wednesday, April 06, 2005 - link

    Many of you are making a huge mistake. You are proposing insane multitasking tests to 'bring these processors to their knees'. This is wrong! Since when do we adjust the review to the product?
    This is similar to only running benchmarks whose working sets fit completely into the 2mb cache of a new cpu. In other words, when you review a product like this, do NOT suddenly change all your variables, keep them as you always had them. Later on, you can adjust variables (tests), and draw your conclusions accordingly.

    Also, I hope people understand that when Anand would have run these test on a dual Xeon 3.2 system, the results would have been virtually the same. You ALREADY KNOW dual cpu systems can be twice as fast as single cpu systems in certain tests, and show no improvement at all in others.

    I really appreciate the article in general, but it would have been SO much better when the PICTURE would have been complete. For this, a dual Opteron system and a dual Xeon system should have been included, AND the tests should have a reflected typical user workloads. If for some reason all cpu's would have been dualcore already, -I- still wouldn't be importing PST files while running my games. Again, when reviewing something, it's wrong to adapt the workload to the product. This is why some people now question your integrety, Anand, because quickly reading through the article DOES give the impression Dual-Core is THE thing, while there's so much it is not!

    And yes, i do realize you don't have dual Opteron/Xeon rigs at hand, but still, you choose to present this incomplete picture. It was a choice, but not necessarily the correct one ;-)


  • Zebo - Wednesday, April 06, 2005 - link

    Anand for game marks I like to see a dvdshrink deep analysis/encode, with grabit downloading 8 threads with plenty more cued, some seti at home, then run farcry and report FPS.:D

    That will bring these single procesors to thier knees obviously but I want to see if DC is really worth it since that's the type of choices I'm forced to choose between.
  • tjahns - Wednesday, April 06, 2005 - link

    As I am not a regular reader nor familiar with the benchmarks used in this article, I am rather disappointed that the scales on the graphs in this article do not indicate what is being measured nor whether "higher is better" or "lower is better". Reply
  • Calin - Wednesday, April 06, 2005 - link

    What would be better in games (I think), especially in first person shooter games, would be to compare the lowest frames per second, and not the highest or the averaged frame rate. And I think this would represent an tremendous advantage for multiprocessors/multicore Reply
  • Calin - Wednesday, April 06, 2005 - link

    "Nice article, as always. I wonder how memory bandwidth increases/decreases will effect the performance of the already bandwidth hungry intel processors."
    The Intel processors are no longer bandwidth hungry, as the move to the 1066FSB showed. However, throw a second processor into the mix, and things might change
  • Calin - Wednesday, April 06, 2005 - link

    The Register has a small review on it, and compare it against a dual Xeon rig
  • Icehawk - Wednesday, April 06, 2005 - link

    Great article - loved the multitasking benchmarks.

    Here's what I have running all the time:

    WinAmp 5
    Outlook 2003
    Firefox 1.02
    Norton A/V2005
    drivers for audio & video :)

    How is my performance affected by multiple Word, Excel, Pshop CS windows? Can I game with them open or do I still need to shut everything down like on my current system? Could I encode a DVD and play a game? Play a DVD off one drive and encode off another?

    As mentioned some of what I want to know is can I do things that currently require me to really run two boxes? I recently moved Azareus (torrent client) and all of my DVD encoding & burning to a second rig.
  • Macro2 - Wednesday, April 06, 2005 - link

    No games tested at all? Since when does this happen? Intel doesn't want dual core to look bad so Anandtech doesn't bench ANY games at all.

    Come on guys, judging by the article below on the Inquirer I'm not the only one who is suspicious.

    Same ole' same ole'
  • snorre - Wednesday, April 06, 2005 - link

    Why did you exclude dual CPU (Opteron/Xeon) systems from your comparisons?

    I recommend that you guys at Anandtech read this:

    Well said! ;-)
  • Bathrone - Tuesday, April 05, 2005 - link

    What about the new extreme edition and I think WinXP only supports a maximum of two cpus? Im not keen to goto 2003 Server. What are Microsoft going to do - patch XP to support 4 cpus? Reply

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