10 Replies Latest reply on Jan 23, 2007 6:12 PM by petedr

    Dual Core or Quad Core?

    JohnGibson Expert

      Ive not seen any research on this, so just a quick grab of peoples views:

       

      With Quad core servers availiable, say blades for example, would you purchase a Quad core server running at half the clock speed of a dual core server?

       

      What are the pros and cons with ESX?

       

      John

        • 1. Re: Dual Core or Quad Core?
          Justin King Enthusiast

          I've not done a ton of research, so II could be a bt off, however this is my understanding:

           

          The new Intel QuadCore processers are not doubling the number of pipelines in addition to Cores, so the performance gain wont be nearly on par as going form a single core to dual core.  Intel also still hasn't gotten rid of its northbridge model yet meaning eveyr core is sharing the bandwidth to memory acess.

           

          Until I see tests that prove otherwise, I just dont see the core2 duo chip design scaling very well past 2 cores.  At 4 it may be better but not perfect so it MAY be an ok investmnet, but when those 8 cores come down the pipe (that some are theorizing) it will be a waste if they dont redesign the chip again.

           

          Again, I've not spend hours or days on this .... this is just from casual reading from differnt RSS feeds.  I'd personally stick with dualcore ... a pair of those would be plenty of power.

          • 2. Re: Dual Core or Quad Core?
            RParker Guru

            No research?  You didn't look hard enough.  do a forum search on Quad Core, there are daily questions about this.

             

            the short answer is NO problems with Quad Core / ESX 3.01.

            • 3. Re: Dual Core or Quad Core?
              Justin King Enthusiast

              I dont htink the question is compatibility problems ... Ithink its which gets you more bang for the buck.  AKA: does VMWare do better with more cores thrown at it vs Mhz.

               

              In this light I think the memory addressing plays a big part, and I dont htink it's fair to only include a discussion of cores vs clock sycles, hence why I brought p staging pipelines and the northbridge.

              • 4. Re: Dual Core or Quad Core?
                RParker Guru

                Well you bring up a good point.  My thing was that this has been discussed, maybe not to include the chipsets, but it's certainly been researched several times.

                 

                I am glad you brought up the chipsets, because that does make a difference.  One reason I want to try an AMD Quad / Dual Core to see if there is any difference there.  It's just like Ford vs Chevy, there are reasons people choose one over the other, and I would like to experiment myself to see if there is a real difference.

                • 5. Re: Dual Core or Quad Core?
                  rock0n Expert
                  VMware Employees

                  Mike has posted an interesting comparison on his site.

                  http://www.rtfm-ed.co.uk/?p=322

                   

                  it doesn't belongs exactly to your question but its very interesting.

                  • 7. Re: Dual Core or Quad Core?
                    juchestyle Master

                    Here is a thought.

                     

                    If you have a dual cpu box, that means you would have an 8 cpu box.  If you want to be able to get 4 - 8 vm's per cpu, you should be able to get between 32 and 64 vm's on that essentially dual cpu box?

                     

                    The obvious question is, do you have enough memory for 32 to 64 vm's? 

                     

                    If you are running a laggard host, meaning that host that runs all the smallest apps, not big importance apps, than maybe you could do this.  But if this is a normal host with a normal mix of vm's, than unless they allow for mega memory, it might not be a good fit.

                     

                    Respectfully,

                    • 8. Re: Dual Core or Quad Core?
                      burnswilcox Enthusiast

                      Well, i have tried using the Quad core Extreme edition from Intel, on a desktop machine. and the performance was rediculous. it is not 4x the power of a single core. But the noticible difference between 2 versus 4 core was present. I only did a few of my tests, since the cpu wasnt mine, and only had 4 hrs to really work with. But when i loaded 8 vms, on it, when it had a e6600, it was good. vms were,

                      1-Domain controller

                      1- Sql server

                      1- citrix server

                      1- password manager server

                      1- acc server.

                      1- web server.

                      1- xp machine

                      1- TSE 4.0 serve with citrix xp on it.

                      Ps i had a VM'ed CAG on my laptop.

                       

                      These are images i had, based on a lab i setup at home.

                       

                      Well the performance was pretty good, but when we swapped out the cpu for the q6600, well the performance was noticable, when i do some of the things that i know would normmally impact the server. Launching the CAG portal, was an immediate improvement. I wouldnt say it was night and day, but the difference was there. and it would warrant the investment.

                      I didnt do anything that would fully TAX the server, but i am suggesting to my clients for future purchases, to go with a  QUAD core cpu, versus a dual core, simple because of the ability to practically run 2x the number of VM's. (more like 1.5) meaning with a dual core, dual machine, with 4 total cores, 16-20 machines, versus a quad core, dual machine with 32-40 machines.

                       

                      For the price, i would do it, Especially considering the same license price.

                      • 9. Re: Dual Core or Quad Core?
                        Illaire Hot Shot

                        If you are running a laggard host, meaning that host

                        that runs all the smallest apps, not big importance

                        apps, than maybe you could do this.  But if this is a

                        normal host with a normal mix of vm's, than unless

                        they allow for mega memory, it might not be a good

                        fit.

                         

                        Our next ESX server will be a quad-core. We're not going to put large amount of memory on it (8 Go probably, perhaps 16). That's the same setup as for our dual-core ESX servers, with a quad core: lots of medium VMs with few high CPU load VMs. We have a load around 50-75% (depending on users and developpers).

                         

                        We except those extra processors to help the scheduler balance the load, and reduce cache misses. ESX 3 is rather good at coscheduling, but I guess extra processors will not do any harm.

                         

                        VMware licensing is based on CPU socket, so we only have to fork some cash to go from dual core to quad core. I think that's fair enough.

                        1 person found this helpful
                        • 10. Re: Dual Core or Quad Core?
                          petedr Virtuoso

                          John,

                           

                          thanks for the Correct, good luck with your server purchases