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
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  • mlittl3 - Tuesday, April 5, 2005 - link

    #90,

    Please, oh, please read Anand's blog from now on. He did just as you are suggesting a couple of days ago before the article was posted/written. He asked the readership for multitasking scenarios and he but those in the article.

    Read his blogs. They are awesome.

    Keep up the good work, Anand and Anandtech staff, and even though you don't have to give into the naysayers about lack of gaming benchmarks, thanks for being understanding and giving the readers what they want.

    That is the sign of true journalistic integrity. :)
  • suryad - Tuesday, April 5, 2005 - link

    As always great work Anand, and for all the users griping about the multitasking testing setup, well maybe Anand would be open to a set of multitasking suggestions his readers most regularly do. Maybe we can all offer suggestions and they will be tested for the second look probably sometime in the future on dual cores and hopefully AMD will have their bad boys out off the cage by then.

    Also benches on Linux would be great...64 bit and 32 bit.

    Surya
  • Anand Lal Shimpi - Tuesday, April 5, 2005 - link

    kjohnson

    I'll let my actions speak for themselves, I've got gaming in Part II and surprisingly enough, it's no different than what I said in Part I - gaming performance of the dual core Pentium D is identical to a single core Pentium 4 of the same clock speed.

    The multitasking tests in Part I were largely determined by responses to a "how do you multitask" question I posted in my blog on Friday. Out of the 65 responses, hardly any mentioned gaming as a multitasking scenario, so given my limited time with the system I decided to focus on what the readers asked for. That's also why I split the article into multiple parts, I knew that more performance testing would be desired but a desire for information would also be there on day one.

    Insinuating that Intel somehow strong armed me into excluding certain benchmarks is just ignorant of how things work, at least at AnandTech. It's a great way to get attention but it's way off base. Intel told me when the system was shipping and when the NDA lifted, no more, no less. I spent all weekend putting together benchmarks that I thought the readership would like to see, not simply re-run benchmarks that we already had results of.

    I've been doing this for 8 years, and the one thing I've always known is that it doesn't matter who is first to publish an article, but it is the article that does the best job and is the most thorough that matters. Trading integrity for exclusivity never makes sense, thinking it does requires a very short term memory and no sense of how things pan out in the long run. Being that in 3 weeks AnandTech will celebrate its 8th year anniversary, I don't think you can argue that type of thinking is characteristic of myself or anyone at this site.

    But I'm not here to try and correct anyone's misconceptions of myself or this site, I'm here to deliver what the readers want and what will help you all make the best, most accurate purchasing decisions. In doing so I've taken every last comment to heart, as I always do, and I'm doing my best to incorporate your requests into Part II...just as I did in Part I.

    As I mentioned in my blog, I'm an open book with nothing to hide, if there are questions of integrity or ethics fire away and I'll be more than happy to answer them.

    Take care,
    Anand
  • Amagus - Tuesday, April 5, 2005 - link

    Wow that Inquirer article basically insinuates that Anand (it's obvious who he's referring to) was bought out because part I of a preview (!!) didn't contain any gaming benchmarks. I wouldn't stand for that.
  • blwest - Tuesday, April 5, 2005 - link

    Nice article, as always. I wonder how memory bandwidth increases/decreases will effect the performance of the already bandwidth hungry intel processors.
  • michael2k - Tuesday, April 5, 2005 - link

    #83, #85

    Gaming wasn't addressed because gaming, by itself, won't see huge improvements with dual core*

    If you run IRC, AIM, FireFox, and BitTorrent while you game, then yes, you will see a performance increase, but not over a single core CPU running only the game by itself. A fast single core CPU will be much, much, better for a game. Or if you run WoW and EQ on two monitors, you will see a benefit.

    *Drastic rewrites of OpenGL and DirectX will see benefits with dual core. For example, if front and back buffers were handled by different CPUs, or if you can split the screen into to sections and have one half processed by one CPU and the other half by another. Another performance technique might be to let one CPU deal with vertex culling, occlusion, and decomposition, while the other CPU deals with shadow calculations, or something suitably complex. But that requires the game to be written for dual core, and won't appear on games already on the market.
  • kjohnson - Tuesday, April 5, 2005 - link

    Here's why this article does not mention any gaming benchmarks:http://www.theinquirer.net/?article=22332.
  • bdchambers79 - Tuesday, April 5, 2005 - link

    I just thought I'd say, I often run the Persistance of Vision Raytracer (www.povray.org) in the background on my computer for several hours (or days... hehe) at a time. While it's running, I am able to do little more than edit text. However, I also like to code and play games.

    So, what I would like to see would be POV-Ray running in the background, with MS Dev Studio or GCC running multiple times in the foreground; or, POV-Ray in the background with a game (NOT necessarily Doom3, guys, though it would be a good benchmark) in the foreground (perhaps in a window, so you can see POV's results). Or, for those truly masochistic souls, POV, DevStudio and Doom3 all running at the same time (though that's less likely to occur in RL) :)
  • BLHealthy4life - Tuesday, April 5, 2005 - link

    I didn't read every single post here, but i do hope that it's ben mentioned that there were wasn't one single game run on this system. Surely this will be done in part two??

  • fitten - Tuesday, April 5, 2005 - link

    #80, that kind of change won't happen withough redigning the memory interface (of either) which would mean that current motherboards wouldn't be able to use the parts (which at least AMD is claiming will be possible).

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