Question regarding the rule of thumb regarding Exchange proc cores ratio to GC proc cores

Hi all,

I am studying towards my MSCE Messaging for Exchange 2013 and came across on CBT nuggets a statement regarding a rule of thumb when it comes to processor cores on Exchange 2013 server to GC

so Greg Shields from CBT nuggets says that the ratio should be

4:1 on x86 domain controllers
8:1 on x64 domain controllers.

So is he talking about 1 mailbox server role with 8 processor cores to 1 processor core on a x64 domain controller? what if there is already a heap of servers using that GC? In our datacentre we have 2 x64 domain controllers but also a whole range of servers on that server network.

Also what if you have 2 mailbox server roles? are we then talking 16 : 2 ?

Hope someone can help clarify this.

Regards
ronnie.jorgensen systems engineer
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