Amazon EBS–optimized instance types
Amazon EBS–optimized instances use an optimized configuration stack and provide additional, dedicated bandwidth for Amazon EBS I/O. This optimization provides the best performance for your EBS volumes by minimizing contention between Amazon EBS I/O and other traffic from your instance.
When attached to an EBS–optimized instance, General Purpose SSD (gp2 and gp3) volumes are designed to
deliver at least 90 percent of their provisioned IOPS performance 99 percent of the time in
a given year, and Provisioned IOPS SSD (io1 and io2) volumes are designed to deliver at least 90 percent of
their provisioned IOPS performance 99.9 percent of the time in a given year. Throughput Optimized HDD
(st1) and Cold HDD (sc1) deliver at least 90 percent of their expected throughput
performance 99 percent of the time in a given year. Non-compliant periods are approximately
uniformly distributed, targeting 99 percent of expected total throughput each hour. For more
information, see Amazon EBS volume types
in the Amazon EBS User Guide.
Some instance types are EBS-optimized by default, and there is no need to enable it and no
effect if you attempt to disable it. Other instance types optionally support EBS optimization
and you can enable it during or after launch for an additional hourly fee
The Amazon EC2 Instance Types Guide indicates which instance types are EBS-optimized by default and which instance types optionally support EBS optimization, along with their Amazon EBS optimized performance. For more information, see the following:
