# Appendix: Amazon EBS SSD storage types
<a name="ebs-storage-types"></a>

Amazon Elastic Block Store (Amazon EBS) provides the following solid state drive (SSD) backed volumes. For the most recent information, see [Amazon EBS volume types](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volume-types.html) in the Amazon EC2 documentation.


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|   | General Purpose SSD | Provisioned IOPS SSD | 
| --- | --- | --- | 
| **Volume type** | `gp3` | `gp2` | `io2 Block Express1` | `io2` | `io1` | 
| **Durability** | 99.8% – 99.9% durability (0.1% – 0.2% annual failure rate) | 99.8% – 99.9% durability (0.1% – 0.2% annual failure rate) | 99.999% durability (0.001% annual failure rate) | 99.999% durability (0.001% annual failure rate) | 99.8% – 99.9% durability (0.1% – 0.2% annual failure rate) | 
| **Use cases** |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/prescriptive-guidance/latest/sql-server-ec2-ha-dr/ebs-storage-types.html) |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/prescriptive-guidance/latest/sql-server-ec2-ha-dr/ebs-storage-types.html) | Workloads that require: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/prescriptive-guidance/latest/sql-server-ec2-ha-dr/ebs-storage-types.html) |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/prescriptive-guidance/latest/sql-server-ec2-ha-dr/ebs-storage-types.html) |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/prescriptive-guidance/latest/sql-server-ec2-ha-dr/ebs-storage-types.html) | 
| **Volume size** | 1 GiB – 16 TiB | 1 GiB – 16 TiB | 4 GiB – 64 TiB | 4 GiB – 16 TiB | 4 GiB – 16 TiB | 
| **Maximum IOPS per volume** (16 KiB I/O) | 16,000 | 16,000 | 256,000 | 64,0002 | 64,0002 | 
| **Maximum throughput per volume** | 1,000 MiB/s | 250 MiB/s3 | 4,000 MiB/s | 1,000 MiB/s2 | 1,000 MiB/s2 | 
| **Amazon EBS Multi-attach** | Not supported | Not supported | Supported | Supported | Supported | 
| **Boot volume** | Supported | Supported | Supported | Supported | Supported | 

1 `io2 Block Express` volumes are supported with R5b instances only. `io2` volumes attached to an `R5b` instance during or after launch automatically run on Block Express. For more information, see [io2 Block Express volumes](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volume-types.html#io2-block-express) in the Amazon EC2 documentation.

 2 Maximum IOPS and throughput are guaranteed only on [instances built on the Nitro System](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances) provisioned with more than 32,000 IOPS. Other instances guarantee up to 32,000 IOPS and 500 MiB/s. `io1` volumes that were created before December 6, 2017 and that have not been modified since creation might not reach full performance unless you [modify the volume](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modify-volume.html).

3 The throughput limit is between 128 MiB/s and 250 MiB/s, depending on the volume size. Volumes smaller than or equal to 170 GiB deliver a maximum throughput of 128 MiB/s. Volumes larger than 170 GiB but smaller than 334 GiB deliver a maximum throughput of 250 MiB/s if burst credits are available. Volumes larger than or equal to 334 GiB deliver 250 MiB/s regardless of burst credits. `gp2` volumes that were created before December 3, 2018 and that have not been modified since creation might not reach full performance unless you [modify the volume](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modify-volume.html).