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Installing VMware on a new Dell server with 2 Intel Xeon E5-2630v2 2.6GHz processors and have a question about Number of cores per processor

Installing VMware on a new Dell server with 2 Intel Xeon E5-2630v2 2.6GHz, 15M Cache, 7.2GT/s QPI, Turbo, HT, 6C, 80W, Max Mem 1600MHz.  Intel says each processor has 6 cores


When I am creating a VM using my VMware Workstaion is asks how many processors and how many cores per processor.  I am a little confused by what I should set this up as.  My long term goal is to run 2 virtual 2012 Standard servers on this new Dell server and have enough resources to spin up a third VM as a backup to another physical 2012 server.

this is what I currently have from VMware

vCenter Server 5 Essentials      1      INSTANCE(s)
vCenter Server 5 Essentials      1      INSTANCE(s)
vSphere 5 Essentials              6      CPU(s)
vSphere 5 Essentials              6      CPU(s)
2 Solutions

I'm not experienced in VMware so much, but what you have there is a total of 2 processors, 12 cores, and 24 threads.  VMware will treat the cores as CPUs so it will look like you have 12 CPUs.

For the 2 servers running 2012 standard, if you know what roles they will have, be sure to study the system requirements for both.  The total amount of Ram was not mentioned but I trust you have at least 16 GB.  Also, I assume you are using 1 or 2 RAID arrays for your hard disks.

I'm not sure if you plan to use these, but Exchange and SQL server are the only products I am familiar with that are multi-threaded meaning they can use more than one core.  So both servers would benefit from having 4 cores.  That uses 8 so you would still have 4 cores left for the 3rd server.  This is of course just a theoretical layout based on the info provided.

Hope this helps.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Always setup and use Sockets, e.g. 1 socket = 1 vCPU.

(only use Cores if you have a licencing restriction only to use Cores).

Performance is the same, whichever you select!

vSMP (virtual SMP) can affect virtual machine performance, when adding too many vCPUs to virtual machines that cannot use the vCPUs effectly, e.g. Servers than can use vSMP correctly :- SQL Server, Exchange Server.

This is true, many VMware Administrators, think adding lots of processors, will increase performance - wrong! (and because they can, they just go silly!). Sometimes there is confusion between cores and processors. But what we are adding is additional processors in the virtual machine.

So 4 vCPU, to the VM is a 4 Way SMP (Quad Processor Server), if you have Enterprise Plus license you can add 8, (and only if you have the correct OS License will the OS recognise them all).

If applications, can take advantage e.g. Exchange, SQL, adding additional processors, can/may increase performance.

So usual rule of thumb is try 1 vCPU, then try 2 vCPU, knock back to 1 vCPU if performance is affected. and only use vSMP if the VM can take advantage.

Example, VM with 4 vCPUs allocated!

My simple laymans explaination of the "scheduler!"

As you have assigned 4 vCPUs, to this VM, the VMware scheulder, has to wait until 4 cores are free and available, to do this, it has to pause the first cores, until the 4th is available, during this timeframe, the paused cores are not available for processes, this is my simplistic view, but bottom line is adding more vCPUs to a VM, may not give you the performance benefits you think, unless the VM, it's applications are optimised for additional vCPUs.

See here

see here


also there is a document here about the CPU scheduler



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