When creating a Blob storage account, there is a performance property available. This property decides whether a standard or a premium storage account is created. For most workloads, standard accounts are more than suitable, but in some cases, more I/O intensive applications need very fast storage. For such cases, the premium storage account was introduced. Premium storage is fully backed by SSD tiers and provides high performance, low latency storage.

Premium storage can currently only be used to store VHD files for Azure IaaS VM solutions. The performance property can't be changed after storage account creation, but it's possible to migrate VMs from the standard to premium storage tier.