Azure Premium Storage Bandwidth Limits

Azure Premium storage is a relatively new Azure feature that lets you replace your standard storage account with high performance, lower latency storage at an additional cost. Throughput of up to 200MB/s can be achieved with a single disk, and even more if multiple disks are combined on a single server.

This all sounds great, but users of Premium Storage may find themselves disappointing when first testing this hardware, and receive less than advertised performance. What is not made entirely clear in the documentation is that the amount of bandwidth to the storage is restricted based on the VM size in use.

A single P30 disk should provide throughput of around 200MB/s however if you attach this to a DS1 virtual machine you won’t see anywhere near this as the VM is limited to throughput of 32MB/s. To get the advertised 200MB/s throughput you would need to make use of a DS4 VM which supports up to 256MB/s.

The maximum throughput supported on the DS series is 512MB/s on a DS14. After that you will need to look at the GS series which goes up to 5000MB/s but at a hefty price.

The full bandwidth list is below:

DS Series

VM SizeMax BandwidthMax IOPS
DS132MB/s3200
DS264MB/s6400
DS3128MB/s12800
DS4256MB/s25600
DS1164MB/s6400
DS12128MB/s12800
DS13256MB/s25600
DS14512MB/s50000

GS Series

VM Size Max Bandwidth Max IOPS
GS1125MB/s5000
GS2250MB/s10000
GS3500MB/s20000
GS41000MB/s40000
GS55000MB/s80000