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Azure compute unit (ACU)

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Applies to: ✔️ Linux VMs ✔️ Windows VMs ✔️ Flexible scale sets ✔️ Uniform scale sets

The concept of the Azure Compute Unit (ACU) provides a way of comparing compute (CPU) performance across Azure SKUs. This will help you easily identify which SKU is most likely to satisfy your performance needs. ACU is currently standardized on a Small (Standard_A1) VM being 100 and all other SKUs then represent approximately how much faster that SKU can run a standard benchmark

*ACUs use Intel® Turbo technology to increase CPU frequency and provide a performance increase. The amount of the performance increase can vary based on the VM size, workload, and other workloads running on the same host.

**ACUs use AMD® Boost technology to increase CPU frequency and provide a performance increase. The amount of the performance increase can vary based on the VM size, workload, and other workloads running on the same host.

***Hyper-threaded and capable of running nested virtualization

****AMD Simultaneous multithreading technology

Important

The ACU is only a guideline. The results for your workload may vary.

SKU Family ACU \ vCPU vCPU: Core
A1_v2 - A8_v2 100 1:1
A2m_v2 - A8m_v2 100 1:1
B Varies 1:1
D1 - D14 160 - 250 1:1
D1_v2 - D15_v2 210 - 250* 1:1
DS1 - DS14 160 - 250 1:1
DS1_v2 - DS15_v2 210 - 250* 1:1
D_v3 160 - 190* 2:1***
Ds_v3 160 - 190* 2:1***
Dav4 230 - 260** 2:1****
Dasv4 230 - 260** 2:1****
Dv4 195 - 210 2:1***
Dsv4 195 - 210 2:1***
Ddv4 195 -210* 2:1***
Ddsv4 195 - 210* 2:1***
E_v3 160 - 190* 2:1***
Es_v3 160 - 190* 2:1***
Eav4 230 - 260** 2:1****
Easv4 230 - 260** 2:1****
Ev4 195 - 210 2:1***
Esv4 195 - 210 2:1***
Edv4 195 - 210* 2:1***
Edsv4 195 - 210* 2:1***
F2s_v2 - F72s_v2 195 - 210* 2:1***
F1 - F16 210 - 250* 1:1
F1s - F16s 210 - 250* 1:1
FX4 - FX48 310 - 340* 2:1***
G1 - G5 180 - 240* 1:1
GS1 - GS5 180 - 240* 1:1
H 290 - 300* 1:1
HB 199 - 216** 1:1
HC 297 - 315* 1:1
L4s - L32s 180 - 240* 1:1
L8s_v2 - L80s_v2 150 - 175** 2:1****
M 160 - 180 2:1***
Mv2 240 - 280 2:1***
NVv4 230 - 260** 2:1****

Processor model information for each SKU is available in the SKU documentation (see links above). Optimal performance may require the latest VM images (OS and VM generation) to ensure the latest updates and fastest drivers.

VM Series Retiring

The following VM series are retiring on or before August 31, 2024:

SKU Family ACU \ vCPU vCPU: Core Retirement Date
H 290 - 300* 1:1 August 31, 2022
HB 199 - 216** 1:1 August 31, 2024
A0 50 1:1 August 31, 2024
A1 - A4 100 1:1 August 31, 2024
A5 - A7 100 1:1 August 31, 2024
A8 - A11 225* 1:1 August 31, 2024

The following GPU series are also retiring:

SKU Family Retirement Date
NC August 31, 2023
NCv2 August 31, 2023
ND August 31, 2023
NV August 31, 2023

Performance Consistency

We understand that Azure customers want the best possible consistent performance, they want to be able to count on getting the same performance from the same type of VM every time.

Azure VM sizes typically run with maximum performance on the hardware platform they are first released on. Azure may place controls on older Azure VMs when run on newer hardware to help maintain consistent performance for our customers even when the VMs run on different hardware. For example:

  1. D, E, and F series VMs may have the processor frequency set to a lower level when running on newer hardware to help achieve better performance consistency across hardware updates. (The specific frequency setting varies based on the processor the VM series was first released on and the comparable performance of the current hardware.)
  2. A series VMs use an older model based on time slicing newer hardware to deliver performance consistency across hardware versions.
  3. B series VMs are burstable and use a credit system (described in their documentation to achieve expected performance.

These different processor settings for VMs are a key part of Azure's effort to provide consistent performance and minimize the impact of changes in underlying hardware platform outside of our customer’s control.

More Info

Here are links to more information about the different sizes: