Create an Azure HPC Cache

Use the Azure portal or the Azure CLI to create your cache.

screenshot of cache overview in Azure portal, with create button at the bottom

Define basic details

Screenshot of project details page in Azure portal.

In Project Details, select the subscription and resource group that will host the cache.

In Service Details, set the cache name and these other attributes:

  • Location - Select one of the supported regions.

    If that region supports availability zones, select the zone that will host your cache resources. Azure HPC Cache is a zonal service.

  • Virtual network - You can select an existing one or create a new virtual network.

  • Subnet - Choose or create a subnet with at least 64 IP addresses (/24). This subnet must be used only for this Azure HPC Cache instance.

Choose cache type and capacity

On the Cache page, specify the type and size of cache to create. These values determine your cache's capabilities, including:

  • How quickly the cache can service client requests
  • How much data the cache can hold
  • Whether or not the cache supports read/write caching mode
  • How many storage targets it can have
  • The cache's cost

First, choose the type of cache you want. Options include:

  • Read-write standard caching - A flexible, general-purpose cache
  • Read-only caching - A high-throughput cache designed to minimize latency for file access

Read more about these cache type options below in Choose the cache type for your needs.

Second, select the cache's capacity. Cache capacity is a combination of two values:

  • Maximum throughput - The data transfer rate for the cache, in GB/second
  • Cache size - The amount of storage allocated for cached data, in TB

Screenshot of cache attributes page in the Azure portal. Fields for Cache type, Maximum throughput, and Cache size are filled in.

Understand throughput and cache size

Several factors can affect your HPC Cache's efficiency, but choosing an appropriate throughput value and cache storage size is one of the most important.

When you choose a throughput value, keep in mind that the actual data transfer rate depends on workload, network speeds, and the type of storage targets.

The values you choose set the maximum throughput for the entire cache system, but some of that is used for overhead tasks. For example, if a client requests a file that isn't already stored in the cache, or if the file is marked as stale, your cache uses some of its throughput to fetch it from back-end storage.

Azure HPC Cache manages which files are cached and pre-loaded to maximize cache hit rates. Cache contents are continuously assessed, and files are moved to long-term storage when they're less frequently accessed.

Choose a cache storage size that can comfortably hold the active set of working files, plus additional space for metadata and other overhead.

Throughput and cache size also affect how many storage targets are supported for a particular cache. If you want to use more than 10 storage targets with your cache, you must choose the highest available cache storage size value available for your throughput size, or choose the high-throughput read-only configuration. Learn more in Add storage targets.

If you need help sizing your cache correctly, contact Microsoft Service and Support.

Choose the cache type for your needs

When you choose your cache capacity, you might notice that some cache types have one fixed cache size, and others let you select from multiple cache size options for each throughput value. This is because they use different styles of cache infrastructure.

  • Standard caches - Cache type Read-write caching

    With standard caches, you can choose from several cache size values. These caches can be configured for read-only or for read and write caching.

  • High-throughput caches - Cache type Read-only caching

    The high-throughput read-only caches are preconfigured with only one cache size option per throughput value. They're designed to optimize file read access only.

Screenshot of the Cache tab in the HPC Cache creation workflow. The Cache type field is filled with Read-write standard caching, and the Maximum throughput field is filled with Up to 4 GB/s. The Cache size menu is expanded and shows several selectable size options: 6 TB, 12 TB, and 24 TB.

This table explains some important differences between the two options.

Attribute Standard cache Read-only high-throughput cache
Cache type "Read-write standard caching" "Read-only caching"
Throughput sizes 2, 4, or 8 GB/sec 4.5, 9, or 16 GB/sec
Cache sizes 3, 6, or 12 TB for 2 GB/sec
6, 12, or 24 TB for 4 GB/sec
12, 24, or 48 TB for 8 GB/sec
21 TB for 4.5 GB/sec
42 TB for 9 GB/sec
84 TB for 16 GB/sec
Maximum number of storage targets 10 or 20 depending on cache size selection 20
Compatible storage target types Azure Blob, on-premises NFS storage, NFS-enabled blob on-premises NFS storage
NFS-enabled blob storage is in preview for this combination
Caching styles Read caching or read-write caching Read caching only
Cache can be stopped to save cost when not needed Yes No

Learn more about these options:

Enable Azure Key Vault encryption (optional)

If you want to manage the encryption keys used for your cache storage, supply your Azure Key Vault information on the Disk encryption keys page. The key vault must be in the same region and in the same subscription as the cache.

You can skip this section if you do not need customer-managed keys. Azure encrypts data with Microsoft-managed keys by default. Read Azure storage encryption to learn more.


You cannot change between Microsoft-managed keys and customer-managed keys after creating the cache.

For a complete explanation of the customer-managed key encryption process, read Use customer-managed encryption keys for Azure HPC Cache.

Screenshot of encryption keys page with "Customer managed" selected and the "Customer key settings" and "Managed identities" configuration forms showing.

Select Customer managed to choose customer-managed key encryption. The key vault specification fields appear. Select the Azure Key Vault to use, then select the key and version to use for this cache. The key must be a 2048-bit RSA key. You can create a new key vault, key, or key version from this page.

Check the Always use current key version box if you want to use automatic key rotation.

If you want to use a specific managed identity for this cache, configure it in the Managed identities section. Read What are managed identities for Azure resources? to learn more.


You cannot change the assigned identity after you create the cache.

If you use a system-assigned managed identity or a user-assigned identity that doesn't already have access to your key vault, there is an extra step you must do after you create the cache. This manual step authorizes the cache's managed identity to use the key vault.

Add resource tags (optional)

The Tags page lets you add resource tags to your Azure HPC Cache instance.

Finish creating the cache

After configuring the new cache, click the Review + create tab. The portal validates your selections and lets you review your choices. If everything is correct, click Create.

Cache creation takes about 10 minutes. You can track the progress in the Azure portal's notifications panel.

screenshot of cache creation "deployment underway" and "notifications" pages in portal

When creation finishes, a notification appears with a link to the new Azure HPC Cache instance, and the cache appears in your subscription's Resources list.

screenshot of Azure HPC Cache instance in Azure portal


If your cache uses customer-managed encryption keys and requires a manual authorization step after creation, the cache might appear in the resources list before its deployment status changes to complete. As soon as the cache's status is Waiting for key you can authorize it to use the key vault.

Next steps

After your cache appears in the Resources list, you can move to the next step.