Public Preview: VM vCore customization features disabling simultaneous multi-threading (SMT/HT) and constrained cores

Azure announces the public preview of VM Customization features, a new capability that gives customers greater control over virtual CPU configurations to optimize performance and licensing costs. This feature introduces two powerful options: Disable Simultaneous Multi-Threading (SMT/HT) and Configurable Constrained Cores. 

With VM Customization, customers can now: 

• Disable Simultaneous Multithreading (SMT/HT) to run VMs with one thread per core for improved performance on latency-sensitive and single-threaded workloads 
• Select a custom vCPU count from a guided list of valid options to reduce software licensing costs while retaining full memory, storage, and I/O bandwidth 

These capabilities are available across a wide range of VM sizes and are supported in select regions during public preview. 

VM Customization offers: 

• Self-service control over Simultaneous Multithreading (SMT/HT)  
• Flexible vCPU selection from validated core count options per VM size 
• Support for both features independently or in combination 
• Reduced licensing costs for software billed per vCPU (e.g., SQL Server, Oracle) 
• Azure Portal, ARM template, CLI and PowerShell support for easy deployment 

These features are ideal for database workloads, HPC scenarios, and customers seeking to optimize licensing costs without sacrificing performance.