Thread: dual processor vs single

  1. #1
    Registered User
    Join Date
    Jul 2004
    Posts
    169

    dual processor vs single

    just out of curisoty, would it be better to have 2 processors going at 1.4 ghz or 1 processor going at 2.8?

  2. #2
    60% Braindead
    Join Date
    Dec 2005
    Posts
    379
    Two processor's can run two threads @ 1.4ghz, one processor can run one @ 2.8ghz. I dont know if the two processors will share one thread though. I'd go with the two, but thats just me :P.
    Code:
    Error W8057 C:\\Life.cpp: Invalid number of arguments in function run(Brain *)

  3. #3
    Sr. Software Engineer filker0's Avatar
    Join Date
    Sep 2005
    Location
    West Virginia
    Posts
    235
    It really depends on your application. Generally, on a SMP system, if 1 CPU at a given clock speed is 100%, 2 CPUs are about 170%-190%, not 200%, as you might expect. That measurement, however, is based on benchmarks which are, by all accounts, somewhat contrived. I've not done the benchmarking myself, so I can't say for sure.

    The lost performance is a result of the fact that the 2 CPUs share resources, and when there is contention for those resources, one CPU has to wait for the other to finish before it can continue. There is also some software overhead, but it's fairly minor.
    Insert obnoxious but pithy remark here

  4. #4
    Registered User
    Join Date
    Sep 2004
    Location
    California
    Posts
    3,268
    just out of curisoty, would it be better to have 2 processors going at 1.4 ghz or 1 processor going at 2.8?
    It would be better to have 1 processor at 2.8ghz.

  5. #5
    Me -=SoKrA=-'s Avatar
    Join Date
    Oct 2002
    Location
    Europe
    Posts
    448
    >It would be better to have 1 processor at 2.8ghz.

    That depends on the workload. Whilst one thread is waiting for the HDD, the other can already be doing stuff. This also happens on a single CPU, but because of the large branches, there is some time that you lose whilst changing the thread. There is also the overhead from having to do interrupts from time to time, though that's hardly noticeable.

    The real issue here is responsivness(sp?) though. Whilst one CPU (or core) is doing one thing, the other one can servicing your request. If you only had one CPU, you'd notice staggering. This only happens at high loads, but when it does happen, you notice it quite a bit.
    SoKrA-BTS "Judge not the program I made, but the one I've yet to code"
    I say what I say, I mean what I mean.
    IDE: emacs + make + gcc and proud of it.

  6. #6
    60% Braindead
    Join Date
    Dec 2005
    Posts
    379
    If you're a serious gamer, go with two. It just seems like games are getting to the point where they're going to use true multithreading :P.
    Code:
    Error W8057 C:\\Life.cpp: Invalid number of arguments in function run(Brain *)

  7. #7
    Cat without Hat CornedBee's Avatar
    Join Date
    Apr 2003
    Posts
    8,895
    I'd say the opposite. Games still rarely use multithreading properly, so the single fast CPU will give you better performance.
    By the time games make relevant use of multithreading, a new CPU might be in order anyway.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  8. #8
    Registered User
    Join Date
    Jul 2004
    Posts
    169
    im looking into this trying to buy a server. getting dual processors starts to get me on the pricey side, so im thinking i might go with a single processor.. for now atleast.

    http://www.newegg.com/Product/Produc...82E16856152019

    im considering this one,

    if anyone happens to know, since this motherboards specs say SATA II hard drives, does this mean it will only take SATA II but not SATA I or will it work wiht SATA I?

    btw this server is going to be for hosting website, i might get dualprocessors for the ones i make for hosting game servers. that way i can run 2 game servers on each machine and assign one to each processor

  9. #9
    Me -=SoKrA=-'s Avatar
    Join Date
    Oct 2002
    Location
    Europe
    Posts
    448
    SATA II is backwards compatible. For example, I'm running this computer with a SATA I harddrive, and my motherboard can do SATA II. It's the same as with IDE/ATAPI. It can do some really fast transfer speeds, but it will also accept your old drives.
    SoKrA-BTS "Judge not the program I made, but the one I've yet to code"
    I say what I say, I mean what I mean.
    IDE: emacs + make + gcc and proud of it.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Single Entry Single Exit
    By robwhit in forum C Programming
    Replies: 5
    Last Post: 11-11-2007, 01:34 PM
  2. buying a laptop ; intel dual core?
    By BobMcGee123 in forum A Brief History of Cprogramming.com
    Replies: 27
    Last Post: 07-30-2006, 02:28 PM
  3. Binary Search Trees Part III
    By Prelude in forum A Brief History of Cprogramming.com
    Replies: 16
    Last Post: 10-02-2004, 03:00 PM
  4. Windows Dual Boot
    By netboy in forum Tech Board
    Replies: 33
    Last Post: 09-15-2003, 11:26 AM
  5. fancy strcpy
    By heat511 in forum C++ Programming
    Replies: 34
    Last Post: 05-01-2002, 04:29 PM