# AWS CloudHSM clusters Making individual HSMs work together in a synchronized, redundant, and highly-available way can be difficult, but AWS CloudHSM does the heavy lifting for you by providing hardware security modules (HSMs) in *clusters*. A cluster is a collection of individual HSMs that AWS CloudHSM keeps in sync. When you perform a task or operation on one HSM in a cluster, the other HSMs in that cluster are automatically kept up to date. AWS CloudHSM offers clusters in two modes: *FIPS* and *non-FIPS*. In FIPS mode, only Federal Information Processing Standard (FIPS) validated keys and algorithms can be used. Non-FIPS mode offers all the keys and algorithms that are supported by AWS CloudHSM, regardless of FIPS approval. AWS CloudHSM also offers two types of HSMs: *hsm1.medium* and *hsm2m.medium*. For details on the differences between each HSM type and cluster mode, see [AWS CloudHSM cluster modes](cluster-hsm-types.md). The *hsm1.medium* HSM type is reaching end of support so new clusters cannot be created with this type. For more information, see [Deprecation notifications](compliance-dep-notif.md#hsm-dep-1) for details. To meet your availability, durability, and scalability goals, you set the number of HSMs in your cluster across multiple availability zones. You can create a cluster that has 1 to 28 HSMs (the [default limit](limits.md) is 6 HSMs per AWS account per [AWS Region](https://docs.aws.amazon.com/cloudhsm/latest/userguide/regions.html)). You can place the HSMs in different [Availability Zones](https://wa.aws.amazon.com/wellarchitected/2020-07-02T19-33-23/wat.concept.az.en.html) in an AWS region. Adding more HSMs to a cluster provides higher performance. Spreading clusters across Availability Zones provides redundancy and high availability. For more information about clusters, see [Clusters in AWS CloudHSM](manage-clusters.md). To create a cluster, see [Getting started](getting-started.md).