Hi,
I am new to SQL and I am not sure if this is in the correct thread but here goes anyway.
We have a Virtual Machine which has SQL server running inside it, the VM currently has 16 vCPU assigned to it, and two SQL instances. we are licensed for 16 cores and each instance is left in its default configuration to balance the CPU usage itself, we don't tie any cores to an instance.
The following link states Limited to lesser of 4 Sockets or 16 cores https://technet.microsoft.com/en-us/library/ms143760(v=sql.110).aspx my question is this: If we assigned 20 vCPU to the VM will SQL only use 16 of them? I guess this is easy to see in task manager if we had one instance, but we have two instances which aren't tied to any cores, so is it possible that instance A will use 16 of 20 cores, and instance B will use a different 16 of 20 cores (with some crossover). What we are trying to avoid is breaking any licensing rules, and also learn how SQL technically uses cores? will the SQLServer.exe process of each instance only have its affinity set to 16 of the cores for example?
Would someone be able to explain this to me, we dont have spare resources to perform a test environment using more than 16 cores, so it's tricky for us to find this out ourselves unless we bring the live system down and assign more cores.
the reason behind this is we think the number of vCPU assigned might be having a bit of a performance impact on the server, but without knowing how each instance balances across the cores and whether we will break licensing rules, it is difficult to move forwards.
Many thanks
Steve