Amazon Elastic Compute Cloud
User Guide for Linux (API Version 2014-10-01)
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Amazon EBS–Optimized Instances

An Amazon EBS–optimized instance uses an optimized configuration stack and provides additional, dedicated capacity for Amazon Elastic Block Store (EBS) I/O. This optimization provides the best performance for your Amazon EBS volumes by minimizing contention between Amazon EBS I/O and other traffic from your instance.

When you use an Amazon EBS–optimized instance, you pay an additional low, hourly fee for the dedicated capacity. For more detailed pricing information, see EBS-optimized Instances on the Amazon EC2 Pricing detail page.

Amazon EBS–optimized instances deliver dedicated throughput to Amazon EBS, with options between 500 Mbps and 4,000 Mbps, depending on the instance type you use. When attached to an Amazon EBS–optimized instance, General Purpose (SSD) volumes are designed to deliver within 10 percent of their of the baseline and burst performance 99.9 percent of the time in a given year, and Provisioned IOPS (SSD) volumes are designed to deliver within 10 percent of their provisioned performance 99.9 percent of the time in a given year. For more information, see Amazon EBS Volume Types.

The following table shows which instance types support EBS-optimization, the dedicated throughput to Amazon EBS, the maximum amount of IOPS the instance can support if you are using a 16 KB I/O size, and the approximate maximum bandwidth available on that connection in MB/s. Be sure to choose an EBS-optimized instance that provides more dedicated EBS throughput than your application needs; otherwise, the EBS to EC2 connection will become a performance bottleneck.

Instance TypeDedicated EBS Throughput (Mbps)*Max 16K IOPS**Max Bandwidth (MB/s)**
c4.large (EBS-optimized by default)5004,00062.5
c4.xlarge (EBS-optimized by default)7506,00093.75
c4.2xlarge (EBS-optimized by default)1,0008,000125
c4.4xlarge (EBS-optimized by default)2,00016,000250
c4.8xlarge (EBS-optimized by default)4,00032,000500

* These instance types must be launched as EBS-optimized to consistently achieve this level of performance.

** This value is a rounded approximation based on a 100% read-only workload and it is provided as a baseline configuration aid. EBS-optimized connections are full-duplex, and can drive more throughput and IOPS in a 50/50 read/write workload where both communication lanes are used. In some cases, network and file system overhead can reduce the maximum throughput and IOPS available.

To launch an Amazon EBS–optimized instance, select the Launch as EBS-optimized instance option in the launch wizard. If the instance type that you've selected can't be launched as an Amazon EBS–optimized instance, this option is not available.

If you launched a supported instance type without enabling EBS-optimization, and you would like to enable it for that instance, you can stop the instance, change the EBS-optimized instance attribute, and restart the instance. For more information, see Modifying a Stopped Instance. If your instance was launched with an instance type that does not support EBS-optimization, but you would like to enable it for that instance, you can resize the instance to a supported instance type, enable EBS-optimization, and restart the instance. For more information, see Resizing Your Instance.