Amazon Relational Database Service
User Guide (API Version 2014-09-01)
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DB Instance Class

The computation and memory capacity of a DB instance is determined by its DB instance class. You can change the CPU and memory available to a DB instance by changing its DB instance class; to change the DB instance class, you must modify the DB instance. For pricing information on DB instance classes, go to the Amazon RDS pricing page.

The following list describes the Amazon RDS DB instance class types and the EC2 instance type it uses:

  • Micro Instances (db.t1.micro) – An instance sufficient for testing but should not be used for production applications. Using a db.t1.micro instance with Oracle is a limited test configuration. We recommend you use db.t1.micro instances with Oracle to test setup and connectivity only; the system resources for a db.t1.micro instance do not meet the recommended configuration for Oracle. No Oracle options are supported on a db.t1.micro instance. For more information, see the Micro Instances topic in the Amazon EC2 documentation.

  • Standard - Current Generation (db.m3) – Second generation instances that provide more computing capacity than the first generation db.m1 instance classes at a lower price.

  • Memory Optimized - Current Generation (db.r3) – Second generation instances that provide memory optimization and more computing capacity than the first generation db.m2 instance classes at a lower price. db.r3 DB instance classes are available for MySQL 5.6, PostgreSQL, and SQL Server DB instances. The db.r3 DB instances classes are not available for Oracle instances, and are not available in the South America (San Paulo), China (Beijing), and GovCloud (US) regions.

    Some SQL Server editions have limitations with db.r3 instances classes. SQL Server Express is not supported with db.r3 instance classes due to Microsoft licensing restrictions. SQL Server Standard and SQL Server Web are limited to db.r3.2xlarge and smaller DB instance classes due to the editions' memory and CPU limitations. Currently, SQL Server Multi-AZ deployments using db.r3 instances classes are only available for SQL Server Standard and SQL Server Enterprise.

    MySQL DB instances created after April 23, 2014 can switch to the db.r3 instance classes by modifying the DB instance just like any other modification. MySQL DB instances running MySQL versions 5.1 or 5.5 and created before April 23, 2014 must use the read replica process shown in Upgrading from MySQL 5.5 to MySQL 5.6. For more information, see the R3 Instances topic in the Amazon EC2 documentation.

  • Burst Capable - Current Generation (db.t2) – Instances that provide baseline performance level with the ability to burst to full CPU usage. This DB instance class requires that the DB instance be in a VPC. Currently, it is not supported in GovCloud and for Multi-AZ deployments in South America (São Paulo). If you have an existing DB instance that you want to move to the db.t2 DB instance class, note that the db.t2 DB instance class requires a VPC; if your current DB instance is not in a VPC, see the topic Moving a DB Instance not in a VPC into a VPC to find out how to move a DB instance not in a VPC into a VPC. For more information about T2 instances used with the db.t2 DB instance class, see the T2 Instances topic in the Amazon EC2 documentation.

    Burst capable instances (db.t2) are available for the following DB engines:

    DB EngineAvailability
    MySQLMySQL version 5.6 supported
    OracleNot supported
    SQL Server
    • SQL Server Express supports db.t2.micro, db.t2.small, and db.t2.medium

    • SQL Server Standard with Bring Your Own License (BYOL) supports db.t2.small and db.t2.medium. SQL Server Standard with License Included (LI) is not supported.

    • SQL Server Web supports db.t2.small and db.t2.medium

    • SQL Server Enterprise with Bring Your Own License (BYOL) supports db.t2.small and db.t2.medium

    • SQL Server Multi-AZ deployments using SQL Server mirroring are supported for SQL Server Standard and SQL Server Enterprise in three regions: US East (Northern Virginia), US West (Oregon), EU (Ireland)

    PostgreSQLAll versions supported

    If you have a DB instance that is supported for db.t2 but that is not in a VPC, you must move the instance into a VPC before you can convert to the db.t2 instance class. For information on moving a DB instance into a VPC, see Moving a DB Instance not in a VPC into a VPC

  • High Memory - Previous Generation (db.cr1) – Instances that are only supported for MySQL 5.6 and PostgreSQL DB instances and are available in the US East (Northern Virginia), US West (Oregon), EU (Ireland), and Asia Pacific (Tokyo) regions. This DB instance class, when used with MySQL 5.6 or PostgreSQL and Provisioned IOPS, can realize up to 20,000 IOPS for MySQL and 25,000 IOPS for PostgreSQL.

  • Memory Optimized - Previous Generation (db.m2) – First generation memory-optimized instances. For more information, see the Instance Type topic in the Amazon EC2 documentation.

  • Standard - Previous Generation (db.m1) – First generation standard instances. For more information, see the Instance Type topic in the Amazon EC2 documentation.

The following table provides details of the Amazon RDS DB instance classes:

Instance ClassvCPUECUMemory (GiB)EBS OptimizedNetwork Performance
Micro Instances     

db.t1.micro

1

1.615NoVery Low

db.m1.small

1

11.7NoVery Low
Standard - Current Generation     

db.m3.medium

1

33.75NoModerate

db.m3.large

2

6.57.5NoModerate

db.m3.xlarge

4

1315500 MbpsModerate

db.m3.2xlarge

8

26301000 MbpsHigh
Memory Optimized - Current Generation     

db.r3.large

2

6.515NoModerate

db.r3.xlarge

4

1330.5500 MbpsModerate

db.r3.2xlarge

8

26611000 MbpsHigh

db.r3.4xlarge

16

521222000 MbpsHigh

db.r3.8xlarge

32

104244No10 GiB
Burst Capable - Current Generation     

db.t2.micro

1

11NoLow

db.t2.small

1

12NoLow

db.t2.medium

2

24NoModerate
Memory Optimized - Previous Generation     

db.m2.xlarge

2

6.517.1NoModerate

db.m2.2xlarge

4

1334.2500 MbpsModerate

db.m2.4xlarge

8

2668.41000 MbpsHigh

db.cr1.8xlarge

32

88244No10 GiB
Standard - Previous Generation     

db.m1.medium

1

23.75NoModerate

db.m1.large

2

47.5500 MbpsModerate

db.m1.xlarge

4

8151000 MbpsHigh

Note

The table column information includes:

  • vCPU – A virtual CPU, or virtual central processing unit, is a unit of capacity that you can use to compare DB instance classes. Instead of purchasing or leasing a particular processor to use for several months or years, you are renting capacity by the hour. Our goal is to provide a consistent amount of CPU capacity no matter what the actual underlying hardware.

  • ECU – The EC2 Compute Unit provides the relative measure of the integer processing power of an Amazon EC2 instance. In order to make it easy for developers to compare CPU capacity between different instance classes, we have defined an Amazon EC2 Compute Unit. The amount of CPU that is allocated to a particular instance is expressed in terms of these EC2 Compute Units. One ECU currently provides CPU capacity equivalent to a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor.

  • Memory (GiB) – Specifies the RAM memory, in gibibytes, allocated to the DB instance. Note that there is often a consistent ratio between memory and vCPU. For example, the db.m1 DB instance class has the same memory to vCPU ratio as the db.m3 DB instance class, but db.m3 instance classes provide better, more consistent performance that db.m1 instances for most use cases. db.m3 instance classes are also less expensive than db.m1 instances.

  • EBS-optimized – DB instance uses an optimized configuration stack and provides additional, dedicated capacity for Amazon 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. For more information about EBS-optimized instances, see the topic Amazon EBS-Optimized Instances in the Amazon EC2 documentation.

  • Network Performance – The network speed relative to other DB instance classes.