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I've got a server running with dual quadcore processors (2 x Intel Xeon L5609), with Windows Server 2008 R2 Standard edition running on top.

The Windows Server Editions Comparison Guide shows that Standard edition can use "X64 Sockets : 4" only. From other documentation, this refers to the amount of logical processors, multiplied by 64 (256). Not exactly sure what this means..

I'm also seeing 8 cores in Task Manager, but I'm unsure if that's physical cores or hyperthreaded duplication.

Can Windows Server 2008 R2 Standard handle only 4 physical cores? Or is the restriction to do with Hyper-V/Virtual machines (which I've seen a lot of google noise about)

Edit: According to a random technet post "Windows Server 2008 Standard Edition can support up to four physical processors, regardless of the number of cores on each processor". I assume that R2 should be the same, but is there any official documentation to back this up?

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up vote 5 down vote accepted

You've got some confused notions.

An x64 socket means a standard x86/x64 physical CPU socket. If you have 2 quad core CPUs in your motherboard, then you have two sockets. The number of cores is irrelevant to Windows Server.

You don't have to multiply anything by anything else.

If it's showing 8 cores in task manager and you have 2 quad cores, then there is no hyper-threading. HT will show two cores in task manager for each physical core if it is enabled.

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As soon as I asked the question, my signal-to-noise on google was clearer, see edit. Thanks for your help :) – glasnt Feb 15 '12 at 20:53
Yeah, the restrictions are the same in R2. I can't find the datasheet now, but there's one floating around on for R2 as well. – MDMarra Feb 15 '12 at 21:00

The restriction refers to physical sockets on the motherboard, individual cores on each socket are counted differently. Therefore, Standard edition can support 4 sockets. Given some of those 12-core AMD monsters, that Standard edition server could have 48 logical cores.

Operating systems can tell the difference between logical and physical cores through some APIC (I believe) table values. Cores on a CPU are still physical CPUs, logical CPUs would be those created for hyperthreading. The APIC table also tells the OS which sockets the cores are attached to, which in turn is used for on those platforms that support it.

All kind of confusing, but in the end, that item on the spec-sheet refers to the sockets on the motherboard.

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