Model EFS bursting credits: baseline throughput, burst ceiling and how long the credit bucket lasts under load.
In Bursting mode an EFS file system earns throughput from the bytes it stores: 50 KiB/s of baseline per GiB, with a credit bucket that lets it run far above that until the credits are gone. Any demand above baseline drains the bucket at exactly the excess rate, so a small file system driving heavy throughput has a runway measured in hours, then collapses to baseline. Buying only the excess as Provisioned Throughput is what turns that cliff into a flat, predictable rate — priced here from a user-supplied list price to confirm on the AWS EFS pricing page for your region. Almost every EFS performance incident is a drained credit bucket rather than a broken workload, and the runway figure tells you how many hours of a batch window you have before the file system throttles.
EFS Performance
baseline MiB/s = GiB x 50 KiB/s ÷ 1024; burst runway hours = credit bucket in MiB ÷ ((demand − baseline) x 3600).
baseline MiB/s = GiB x 50 KiB/s ÷ 1024; burst runway hours = credit bucket in MiB ÷ ((demand − baseline) x 3600). In Bursting mode an EFS file system earns throughput from the bytes it stores: 50 KiB/s of baseline per GiB, with a credit bucket that lets it run far above that until the credits are gone. Any demand above baseline drains the bucket at exactly the excess rate, so a small file system driving heavy throughput has a runway measured in hours, then collapses to baseline. Buying only the excess as Provisioned Throughput is what turns that cliff into a flat, predictable rate — priced here from a user-supplied list price to confirm on the AWS EFS pricing page for your region.
Almost every EFS performance incident is a drained credit bucket rather than a broken workload, and the runway figure tells you how many hours of a batch window you have before the file system throttles.
This calculator takes 6 inputs: Standard-tier data in the file system, Baseline throughput earned per GiB, Burst throughput per TiB, Credit bucket size per TiB stored, Sustained throughput the workload drives, Provisioned throughput price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Elastic removes the credit model entirely and bills per GB read and written, which suits spiky, unpredictable workloads. Bursting is cheaper for steady access that fits inside the baseline the stored data already earns.