Results 1 to 16 of 16
  1. #1
    Join Date
    Aug 2004
    Location
    Tor-NY-BJ
    Posts
    330

    Dual Core vs Dual CPU

    Which is a better solution? Is SMP needed for Dual Core as well? Or CPU will allocate cores automatically, and from OS, it only sees 1 CPU?
    Trusted

  2. #2
    I'd be interested in the answer to the SMP/OS question also...anyone have experience with dual cores that would like to shed some light?

  3. #3
    Join Date
    Jan 2004
    Location
    Texas
    Posts
    1,556
    Well, I haven't gotten to play with them yet, but they are supposed to show as two CPUs in the system. So.. Yes, SMP (Symetric Multi Processor) would be needed.
    James Lumby

  4. #4
    Join Date
    Feb 2001
    Location
    Solar Star system
    Posts
    183

    Re: Dual Core vs Dual CPU

    Originally posted by qllonceagain
    Which is a better solution? Is SMP needed for Dual Core as well? Or CPU will allocate cores automatically, and from OS, it only sees 1 CPU?
    My opinion so fare is this.

    It's better to go DUAL PURE CPU server if u can - but it's nice if u have dual cpu server + dual core.

    We plan to upgrade some dual CPU server's with dual core cpu's.

    If u go with SINGLE CPU - but dual core - you will get worst results then if u have actually 2 cpu's in server's.

    So fare I have no exp with dual core intel but there is some issues with curent technology regarding dual core cpu's that Intel is using.

    As u can read here:

    http://www.anandtech.com/cpuchipsets...oc.aspx?i=2419

    Also benchmarks INTEL dual vs AMD dual.

    http://www.anandtech.com/cpuchipsets...spx?i=2397&p=1

    But the bottom line is the

    If u can have PURE quad OPTERON or PURE quad XEON server - it will be faster then dual opteron dual core or dual xeon dual core.

    But ofcourse it's way expensive to have PURE quad server, so dual core look's like a nice bargin really.

    Mostly all curent opteron server can be upgrade with X2 CPU's - so your curent dual optern can get a nice CPU boost if u ever need it.

    N.

  5. #5
    The tendancy is to put dual core in smaller cases, so heat would be a problem. Dual CPU however encourages you to use a alrger case

  6. #6
    Join Date
    Jan 2004
    Location
    Chicago
    Posts
    984
    While I'd like to see some solid comparisons of dual core vs dual cpu performance, the bonus to dual core is licensing per socket, so you should be able to get more bang for your buck with a single socket dual core if you're paying per cpu licensing fees on software.

  7. #7
    Join Date
    Aug 2004
    Location
    Tor-NY-BJ
    Posts
    330
    Dual Core Intel is NONO, because the dual core does not talk to each other directly

    Dual Core AMD use direct connect for speed.

    I thought OS will only see Dual Core as 1 CPU, because OS talks to L2 Cache only and L2 talks to each core's L1
    Trusted

  8. #8
    Join Date
    Jan 2003
    Posts
    1,715
    Nope. CPU cache is invisible to the OS -- cache misses and pipeline stalls look the same as any other CPU usage. The Opteron dual-core will have separate L2 caches, anyway (not sure about the Intel). Some architectures count cache misses for performance measurement, but the OS never directly controls the cache.

    You WILL need an SMP aware OS to balance tasks across both cores, just like you need it for Hyper-Threading in the current Xeons. Separate chips will perform better than dual-core, but at a non-trivial cost increase. Dual-core will give you better bang for your buck.
    Game Servers are the next hot market!
    Slim margins, heavy support, fickle customers, and moronic suppliers!
    Start your own today!

  9. #9
    Originally posted by hiryuu
    Nope. CPU cache is invisible to the OS -- cache misses and pipeline stalls look the same as any other CPU usage. The Opteron dual-core will have separate L2 caches, anyway (not sure about the Intel). Some architectures count cache misses for performance measurement, but the OS never directly controls the cache.

    You WILL need an SMP aware OS to balance tasks across both cores, just like you need it for Hyper-Threading in the current Xeons. Separate chips will perform better than dual-core, but at a non-trivial cost increase. Dual-core will give you better bang for your buck.
    It depends. Dual core - in case of AMD, not that lame 'double core' Intel chip - has a built-in crossbar etc, so no need to go out to the chipset, unlike in case of dual chips.

  10. #10
    The bottomline is the multi core is new technology and both companies will need time to work out the bugs. Yes qllonceagain intels don't talk directly together but I am sorry to tell you Amd has issue to. Just read this about the X2 which suffers memory bandwith.

    "On the downside, the X2 series does suffer in comparison to the PD and the PEE in terms of memory bandwidth. While limited by the frontside bus, Intel chipsets provide more memory bandwidth for the two cores than AMD’s. That said, neither is in an ideal position here. In both manufacturers' architectures each of the processor cores is forced to share RAM that was previously designated for only one processor. These circumstances should improve as AMD and Intel research and develop more powerful chipset designs." http://informationweek.smallbizpipel...owto/166401016
    Last edited by Deepbluehosting; 08-04-2005 at 04:05 PM.

  11. #11
    Join Date
    Apr 2005
    Posts
    175
    Always quote your sources

    That is what I can add.

  12. #12
    Originally posted by Deepbluehosting
    The bottomline is the multi core is new technology and both companies will need time to work out the bugs. Yes qllonceagain intels don't talk directly together but I am sorry to tell you Amd has issue to. Just read this about the X2 which suffers memory bandwith.

    "On the downside, the X2 series does suffer in comparison to the PD and the PEE in terms of memory bandwidth. While limited by the frontside bus, Intel chipsets provide more memory bandwidth for the two cores than AMD’s. That said, neither is in an ideal position here. In both manufacturers' architectures each of the processor cores is forced to share RAM that was previously designated for only one processor. These circumstances should improve as AMD and Intel research and develop more powerful chipset designs." informationweek.smallbizpipeline.com/howto/166401016
    "Intel chipsets provide more memory bandwidth for the two cores than AMD’s. "

    Ouch. Another misinformed article, another ill-informed writer.
    Intel's DDR2 has much higher latency by default - on top of the latency caused complete lack of integrated memory controller which makes all the A64/Opteron-family so killer chips.
    Writer should go back and learn how a CPU works.

  13. #13
    I've got two boxes in house here with dual core in them, one with an x2 4800+ and one with an 830 intel.

    Both chips are recoginized as two processors by windows server, centos, and fedora. For the cost of an intel dual core vs performance, there is a significant gain. For the cost of an amd and supporting motherboard (1k +), you could purchase a low end or mid grade dual xeon and have much higher performance. And better scalability.

    Hope this helps.

    Kudos.
    www.Phsynet.com
    Phsynet Hosting Solutions || Personable, Professional hosting and design.
    AIM: Phsynet
    Email: [email protected]

  14. #14
    Join Date
    May 2005
    Location
    AS65531
    Posts
    2
    SMP latency is non existant with dual cores.

  15. #15
    Originally posted by Monk of BORG
    SMP latency is non existant with dual cores.
    Really? And how so?

  16. #16
    Join Date
    Dec 2004
    Location
    Seabrook, NH (seacoast)
    Posts
    78
    I'm somewhat interested as to where you guys get these kinds of disinformation. Let me start at the head of the snake though. I have in colo right now a Tyan B2881 / 1U system I built and shipped to Chicago. It has 270's in it. First of all, the memory is not "shared' in our setup. Research something called NUMA that allows any cpu to address/use any RAM on the board. Second, the hyper tunnel connection of the two cores happen at 1GHz speed bus, the bus speed to the RAM is also 1GHz and in the event as we use D-DDR it happens at 2000MHz as the hardware sites reference from time to time. The technology that has been referenced in this thread so far has been comparing apples to oranges and here's exactly where that is happening. Xeon is the enterprise cpu of Intel. X2 is NOT AMD's enterprise cpu. Opterons are. If you compare apples to apples the dual core Opterons, like the 270s we use, they beat the pants off of the Intels in pretty much every catagory. I'd be interested to see ANY reviews showing otherwise. The internal architecture of the Opterons are far superior to the Intel Xeon chips and additionally run at x64 much more efficiently that their Intel counterparts.

    Now, for brute speed the dual cpus do seem to be the favored setup. The industry is producing dual cores to allow more computing power in the same cpu slot while still reducing heat. That goal they have completely accomplished. There is, to our knowledge, no bugs involved in the dual core setup we use. Again, we are NOT using X2s as they are not enterprise equipment but more of a highend consumer product. The 2MB L2 cache in the dual core 270 Opteron is for EACH core. So literally there is 2 x (64+64 L1)(2MB L2) on each chip as a whole. Heatwise, you'll find that researching what type of cases are recommended vary from vendor to vendor. We chose a Tyan barebone 2881 that comes in a 1U and can fully support our needs and issues no heat concerns. The cpus are kooled by 5 x 1" fans running at variable speeds up to 15Krpm and keep the system perfectly cooled in the case even under full load during our 2 day break-in period.

    If you're going to compare consumer level cpus then compare X2s to a dual-core counterpart from Intel in the P4 line of products. If you're going to use Intel Xeons as one side then compare them to their much more capable competition in the Opteron lines.

    I hope to see a more fair comparison of hardware as this thread progresses.

    In the way of the OS being used; the OS sees two separate cpus per core so in a dual core, dual cpu setup the OS would need to be able to utilize a 4-cpu setup. I believe the licensing from most software vendors are moving to a "per socket" platform and that is part of the drive behind the dual core phase we're seeing. The other driving factor is heat versus power consumption and space limitations. As we have a 4-cpu setup in a 1U rackmount you can see that advantage in our usage.
    ::RaynServ Web Hosting:: - Powerful Performance for Web Hosting
    Low Cost CPanel RESELLER Plans and Shared Hosting!!! 99.9% Uptime!!
    When Performance Matters

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •