# Provisioned IOPS SSD Volumes

* **`io1` volumes are designed to meet the needs of I/O-intensive workloads**, particularly database workloads, that are sensitive to storage performance and consistency.\

* **Unlike `gp2`, which uses a bucket and credit model to calculate performance, an `io1` volume allows you to specify a consistent IOPS rate** when you create the volume, and EBS delivers within 10 percent of the provisioned IOPS performance 99.9 percent of the time over a given year.\

* An **`io1` volume can range in size from 4 GiB to 16 TiB**.\

*   You can **provision from 100 IOPS up to 64,000 IOPS per volume on Nitro system instance** families and up to 32,000 on other instance families.


* The **maximum ratio of provisioned IOPS to requested volume size (in GiB) is 50:1**.\

  * For example, a **100 GiB volume can be provisioned with up to 5,000 IOPS**.
