General availability of new Azure disk sizes and bursting

Posted on April 1, 2020

Program Manager, Azure Storage

Today marks the general availability of new Azure disk sizes, including 4, 8, and 16 GiB on both Premium and Standard SSDs, as well as bursting support on Azure Premium SSD Disks.

To provide the best performance and cost balance for your production workloads, we are making significant improvements to our portfolio of Azure Premium SSD disks. With bursting, even the smallest Premium SSD disks (4 GiB) can now achieve up to 3,500 input/output operations per second (IOPS) and 170 MiB/second. If you have experienced jitters in disk IOs due to unpredictable load and spiky traffic patterns, migrate to Azure and improve your overall performance by taking advantage of bursting support.

We offer disk bursting on a credit-based system. You accumulate credits when traffic is below the provisioned target and you consume credit when traffic exceeds it. It can be best leveraged for OS disks to accelerate virtual machine (VM) boot or data disks to accommodate spiky traffic. For example, if you conduct a SQL checkpoint or your application issues IO flushes to persist the data, there will be a sudden increase of writes against the attached disk. Disk bursting will give you the headroom to accommodate the expected and unexpected change in load.

Disk bursting will be enabled by default for all new deployments of burst eligible disks with no user action required. For any existing Premium SSD Managed Disks (less than or equal to 512GiB/P20), whenever your disk is reattached or VM is restarted, disk bursting will start to take effect and your workloads can then experience a boost on disk performance. To read more about how disk bursting works, refer to this Premium SSD bursting article.

Further, the new disk sizes introduced on Standard SSD disk provide you the most cost-efficient SSD offering in the cloud, providing consistent disk performance at the lowest cost per GiB. We've also increased the performance target for all Standard SSD disks less than 64GiB (E6) to 500 IOPS. It is an ideal replacement of HDD based disk storage from either on-premises or cloud. It is best suited for hosting web servers, business applications that are not IO intensive but require stable and predictable performance for your business operations.

In this post, we’ll be sharing how you can start leveraging these new disk capabilities to build your most high performance, robust, and cost-efficient solution on Azure today.

Getting started

You can create new managed disks using the Azure portal, Powershell, or command-line interface (CLI) now. You can find the specifications of burst eligible and new disk sizes in the table below. Both new disk sizes and bursting support on Premium SSD Disks are available in all regions in Azure Public Cloud, with support for sovereign clouds coming soon.

Azure Premium SSD Managed Disks

Here are the burst eligible disks including the newly introduced sizes. Disk bursting doesn’t apply to disk sizes greater than 512 GiB (above P20) as the provisioned target of these sizes are sufficient for most workloads.  To learn more details on the disk sizes and performance targets, please refer to this "What disk types are available in Azure?" article.

30 mins

Burst capable disks Disk size Provisioned IOPS per disk Provisioned bandwidth per disk Max burst IOPS per disk Max burst bandwidth per disk Max burst duration at peak burst rate
P1—New 4 GiB 120 25 MiB/second 3,500 170 MiB/second 30 minutes
P2—New 8 GiB 120 25 MiB/second 3,500 170 MiB/second 30 minutes
P3—New 16 GiB 120 25 MiB/second 3,500 170 MiB/second

30 minutes

P4 32 GiB 120 25 MiB/second 3,500

170 MiB/second

30 minutes

P6 64 GiB 240 50 MiB/second 3,500

170 MiB/second

30 minutes
P10 128 GiB 500 100 MiB/second 3,500

170 MiB/second

30 minutes
P15 256 GiB 1,100 125 MiB/second 3,500 170/MiB/second 30 minutes
P20 512 GiB 2,300 150 MiB/second 3,500

170 MiB/second

30 minutes

Standard SSD Managed Disks

Here are the new disk sizes introduced on Standard SSD Disks. The performance targets define the max IOPS and bandwidth you can achieve on these sizes. Unlike Premium Disks, Standard SSD does not offer provisioned IOPS and bandwidth. For your performance-sensitive workloads or single instance deployment, we recommend leveraging Premium SSDs.    

  Disk size Max IOPS per disk Max bandwidth per disk
E1—New 4 GiB 500 25 MiB/second
E2—New 8 GiB 500 25 MiB/second
E3—New 16 GiB 500 25 MiB/second


Visit our service website to explore the Azure Disk Storage portfolio. To learn about pricing, you can visit the Azure Managed Disks pricing page

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