What throughput modes are available in EFS and what is the right throughput mode for my workload?

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Throughput mode determines the throughput that's available to your file system. Amazon EFS offers three throughput modes: Bursting Throughput mode, Provisioned Throughput mode, and Elastic Throughput mode.

Bursting Throughput mode

Bursting Throughput mode is the default Amazon EFS throughput mode. In Bursting Throughput mode, file system baseline throughput is proportional to the file system size in the EFS standard storage or One-Zone storage class. The maximum throughput value depends on your AWS Region for Amazon EFS. For more information about per-Region limits, see the table in Amazon EFS quotas that you can increase.

Because read and write throughput are metered, Amazon EFS deducts burst credits from the burst credit balance. When the metered throughput is lower than the baseline throughput, Bursting Throughput mode uses burst buckets to save burst credits. However, when the metered throughput is higher than the baseline throughput, this mode uses burst credits.

For more information on metered throughput, see the Understanding metered throughput section in Throughput modes.

The baseline performance per GiB of file system storage is 50 KiB/s (the equivalent of 50 MiB/s per TiB of storage). All EFS file systems, regardless of size, can burst up to 100 MiB/s of metered throughput, if they have burst credits. For file systems above 1 TiB, the burst throughput is twice the baseline performance. For example, a 2-TiB file system has a baseline performance of 100 MiB/s and can burst up to 200 MiB/s. After all burst credits are used, Amazon EFS throttles the file system to drive baseline performance.

For more information on burst credits, see How do Amazon EFS burst credits work?

Provisioned Throughput mode

Provisioned Throughput mode allows you to provision throughput for your file system (in MiB/s) regardless of how much data you store in your file system. However, this mode also incurs additional charges. These charges are based on the storage that you use and the throughput that you provision that exceeds what you're initially provided. The amount of throughput that you're provided is based on the amount of data that's stored in the EFS Standard or EFS One Zone storage class.

Note: If your system's metered size provides a higher baseline rate than the amount of provisioned throughput, then your system follows the default Bursting Throughput model. You don't incur charges for Provisioned Throughput below your file system's entitlement in Bursting Throughput mode.

Elastic Throughput mode

Elastic Throughput mode determines your amount of metered throughput based on the amount of data that you read and write. You incur charges only from the data that you use. This mode dynamically adjusts throughput capacity based on your workload, so you don't need to provision your throughput capacity. While in Elastic Throughput mode, you don't accrue or consume any burst credits.

For more information, see Announcing Amazon EFS Elastic Throughput.

Note: Elastic Throughput mode is available only for file systems that are configured with the General Purpose performance mode.

How to decide which throughput mode is suitable for your workload

If your workloads typically spike in usage, then use Bursting Throughput mode or Elastic Throughput mode. A spiky workload drives high levels of throughput for short periods of time, with otherwise low levels of throughput. For throughput that scales with the amount of storage in your file system, it's a best practice to use Bursting Throughput mode. For applications that require additional throughput, or when you have no remaining burst credits, use Elastic Throughput mode.

For applications that have a relatively constant throughput, use Provisioned Throughput mode. Before you switch to Provisioned Throughput mode, consider how much throughput you need to provision. To determine your minimum amount of Provisioned Throughput, check the Average Throughput usage for your file system for the previous two weeks. Note the highest peak amount, rounded up to the next megabyte.

Related information

Throughput modes

Managing file system throughput