SQL Server vCPUs and Performance I'm hoping to get some information on how vCPU performance changes (if any) based on guest vCPU configuration in a VMWare environment. Not really worried about the licensing aspect, or SKU specific limitations here (that's a whole other can of worms I don't want to get into). 

Most of my SQL Servers are configured as:


CPU: 4
Cores per Socket: 1 (Sockets: 4)


I noticed one of my servers was configured differently with more 'Cores per Socket' to achieve 6 vCPUs:


CPU: 6
Cores per Socket: 3 (Sockets: 2)


I know there are CPU/Memory limitations based on SKU but for simplicity's sake I'm really just wondering which might be the better configuration:


A: more 'CPU'
B: more 'Cores per Socket' 
C: neither, it does not matter! :-o


Here's the output of SELECT node_id, online_scheduler_count FROM sys.dm_os_nodes:

On the 4 vCPU system

NODE_ID  ONLINE_SCHEDULER_COUNT 
0        4 
64       1 


And on the 6 vCPU system

NODE_ID  ONLINE_SCHEDULER_COUNT 
0        6 
64       1
Community wiki answer:


  I'm really just wondering which might be the better configuration


On the low end workload spectrum, you probably won't notice a difference. On the higher workload spectrum I'd copy or come close to the underlying hardware setup.

Note that depending on the version of ESXi you use, having less than 8 vCPUs won't actually change the cores/node and you may have to edit the virtual machine config file to override the changes in default behaviour.



The output from the sys.dm_os_nodes query shows that VMWare overrode your config and gave you a single NUMA node.