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

  • haveblue128 - Wednesday, July 6, 2005 - link

    Only downside but I think a majorleague heat solution should make everything sweet Reply
  • haveblue128 - Wednesday, July 6, 2005 - link

    Oh Please give us a break. If you want to be a purist, go live in the woods without clothes. I say that multitasking makes my day a breeze.
    Whats your dilemma??
  • haveblue128 - Wednesday, July 6, 2005 - link

    Wow-I just purchased a new sys with an Intel Dual CPU setup. As a multitasking monster on my machine, I was always having crashes in the past.
    I think that is gone with George Bush in 2008. THe good news is the dual core pair is already hear and ready to run. Give them a try-no downside, albeit a good bit of heat. That is something I will need to work on, but....
  • peufeu - Monday, May 9, 2005 - link

    I forgot to mention... gentoo linux ;) Reply
  • peufeu - Monday, May 9, 2005 - link

    Dual CPUs to compensate for the inept MS Windows.

    I'm torturing a webserver I just wrote, on my laptop. It's in Python. Right now it's serving about 2000 requests per second with 1000 concurrent connections.

    I don't even notice it's running. The CPU gauge is at 100%, so what ? Nothing special. As reactive as usual. It doesn't swap. The harddisk even put itself in standby....

    Go, bill, go !

  • shady28 - Sunday, April 17, 2005 - link

    Making special tests just for these processors seems a bit contrived to me. In particular, comparing dual core processors to a Pentium 4 with HT disabled, in a multithreading/multitasking benchmark, is just plane lame.

    I would have been a lot more interested in seeing how dual core compares in multitasking vs dual opterons or dual Xeons. Right now it looks like dual core is slower at doing one task at a time, suprisingly not that much faster at doing two tasks at a time than HT Pentium 4s. The only exceptions were the off the wall tests done at the end.

    Since these new 'benchmarks' are made to simulate 'real life use', does that mean that all Anand's previous reviews were bogus?

  • JimGunn - Wednesday, April 13, 2005 - link

    I think I will want one of these for my next video editing & encoding workstation. Will come in handy for HDV post I am sure! Reply
  • BoBOh - Monday, April 11, 2005 - link

    Where are the code compile tests. We're not all gamers, some are software developers! :)

  • warath - Friday, April 8, 2005 - link

    I can't wait to see 64-bit dual cores! :) Reply
  • WoodenPupa - Thursday, April 7, 2005 - link

    Well, I'm not a tech whiz like everyone else here, but here's my 2 centavos...

    I can attest to the fact that every machine I ever buy, I bring it to its knees. I usually wait several generations before I upgrade in order to get a more profound effect. Yet that strategy doesn't seem to matter because no matter how fast my computer is, I find that my NORMAL computing habits end up crushing the CPU and everything else.

    I use Cool Edit Pro and some other audio programs, and I am also a chess player, and like to anyalyze games in the background with Fritz or Chessbase, both of which allow for gigantic hash tables. So as a typical case I like to do wave transforms and chess analysis as background items while I compose e-mails or use Word for more serious writing. Naturally I like to listen to music at the same time, but usually I have to give that up. Needless to say, all of this stuff cripples my computer---I'm due for an upgrade, I know---my box is a 2.53 GHz P4, 1 GB of Rambus 800 (no groaning, please), a GF4 ti 4600, 120 GB HD, I'm not even sure what the cache on that is, I don't think it's 8 or 5 MB---feels more like 2.

    I usually end up quitting the Chess program or the Mp3 player---once in a while I can do all of this stuff concurrently if the wave transforms on cool edit aren't too complex, and I minimize the hash tables on the chess program.

    Ideally I want everything to be instantaneous, but...:) Anyway, from what it sounds like, I need a dual or even quad processor setup. Because even with all the above mentioned programs running, I can think of more I would like to add. I'm a monster multitasker and really like to kick a computer right in the face, to show it who's boss. I'm tired of winning, though---I'd love it if one day the computer just scoffed at everything I threw at it. Sadly, I don't think it'll happen in my lifetime.

    Should I upgrade to a dual core, or should I save and get a true multi-CPU Mobo like a quad Xeon??

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