Azure Compute Unit Compares VM Performance

• Azure Compute Unit is a measure that compares relative performance of Azure VMs.
• It could help customers determine which Azure VMs provide the best performance value while meeting workload requirements.
• It is found only in Microsoft documentation and not in other tools used to choose VMs.

Azure Compute Unit (ACU) is a Microsoft-supplied measure that customers can use to compare relative CPU performance across Azure VM series. (It does not compare other VM characteristics, such as memory and disk input/output operations per second [IOPS].)

Perf Provided Relative to Base VM Series

The wide selection of Azure VM series, which vary by processor type, number of cores, memory, speed, and targeted use cases, often makes it difficult for customers to identify the best for their workload requirements while optimizing cost. Additionally, performance differences among processors are difficult to determine because they depend on several processor aspects other than clock speed.

ACU is a number assigned to Azure VM series indicating relative performance using series A VMs as a baseline. Series A VMs are assigned an ACU of 100 per virtual CPU (vCPU). Other examples of ACU ratings include the following: