Record threads per core separately from an Azure VM’s available vCPUs

Source facts

Microsoft describes separate settings for threads per core and the available vCPU count. Setting threads per core to one disables simultaneous multithreading. The portal presents valid available-vCPU values for the selected VM size. Microsoft states that the base VM price is unchanged by these CPU configuration options. Microsoft Learn

Applicability

This guide is for a team requesting CPU customization during Azure VM creation and preparing to validate what the guest operating system receives.

DSE recommendation

DSE recommends writing both requested settings into the deployment specification alongside the exact VM size. Have the workload owner explain the operational reason for each choice and define a representative performance test before deployment. Keep any software-license assessment separate and obtain the relevant owner’s interpretation rather than promising savings from a lower CPU count. Review the valid values shown for the selected size before submitting the request.

Verification

Compare the deployed hardware profile with the specification and inspect the processors visible to the guest. Run the agreed workload checks and retain the configuration with the results. If the observed CPU presentation differs from the request, investigate that mismatch before using the VM as the basis for performance or licensing conclusions.

Official references

• Microsoft: VM vCore Customization – Azure Virtual Machines | Microsoft Learn