# RDS for Oracle DB instance classes
<a name="Oracle.Concepts.InstanceClasses"></a>

The computation and memory capacity of an RDS for Oracle DB instance is determined by its instance class. The DB instance class you need depends on your processing power and memory requirements.



## Supported RDS for Oracle DB instance classes
<a name="Oracle.Concepts.InstanceClasses.Supported"></a>

The supported RDS for Oracle instance classes are a subset of the RDS DB instance classes. For the complete list of RDS instance classes, see [DB instance classes](Concepts.DBInstanceClass.md).



### RDS for Oracle preconfigured DB instance classes
<a name="Oracle.Concepts.InstanceClasses.Supported.tpc"></a>

RDS for Oracle also offers instance classes that are preconfigured for workloads that require additional memory, storage, and I/O per vCPU. These instance classes use the following naming convention.

```
db.r5b.instance_size.tpcthreads_per_core.memratio
db.r5.instance_size.tpcthreads_per_core.memratio
```

The following is an example of an instance class that is preconfigured for additional memory:

```
db.r5b.4xlarge.tpc2.mem2x
```

The components of the preceding instance class name are as follows:
+ `db.r5b.4xlarge` – The name of the instance class.
+ `tpc2` – The threads per core. A value of 2 means that multithreading is turned on. A value of 1 means that multithreading is turned off. 
+ `mem2x` – The ratio of additional memory to the standard memory for the instance class. In this example, the optimization provides twice as much memory as a standard db.r5.4xlarge DB instance. 

**Note**  
For the normalization factors of the preconfigured RDS for Oracle DB instance classes, see [Hardware specifications for DB instance classes](Concepts.DBInstanceClass.Summary.md).

### Supported edition, instance class, and licensing combinations in RDS for Oracle
<a name="Oracle.Concepts.InstanceClasses.Supported.combo"></a>

If you're using the RDS console, you can find out whether a specific edition, instance class, and license combination is supported by choosing **Create database** and specifying different option. In the AWS CLI, you can run the following command:

```
aws rds describe-orderable-db-instance-options --engine engine-type --license-model license-type
```

The following table lists all editions, instance classes, and license types supported for RDS for Oracle. For information about the memory attributes of each type, see [ RDS for Oracle instance types](https://aws.amazon.com//rds/oracle/instance-types). For information about pricing, see [Amazon RDS for Oracle pricing models](https://aws.amazon.com/rds/oracle/pricing/#Pricing_models).


****  
<a name="rds-oracle-instance-class-reference"></a>[\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Oracle.Concepts.InstanceClasses.html)

## Deprecated RDS for Oracle DB instance classes
<a name="Oracle.Concepts.InstanceClasses.Deprecated"></a>

The following DB instance classes are deprecated for RDS for Oracle:
+ db.m1, db.m2, db.m3, db.m4
+ db.t1, db.t2
+ db.r1, db.r2, db.r3, db.r4
+ db.x1, db.x1e

The preceding DB instance classes have been replaced by better performing DB instance classes that are generally available at a lower cost. If you have DB instances that use deprecated DB instance classes, you have the following options:
+ Allow Amazon RDS to modify each DB instance automatically to use a comparable non-deprecated DB instance class. For deprecation timelines, see [DB instance class types](Concepts.DBInstanceClass.Types.md).
+ Change the DB instance class yourself by modifying the DB instance. For more information, see [Modifying an Amazon RDS DB instance](Overview.DBInstance.Modifying.md). 

**Note**  
If you have DB snapshots of DB instances that were using deprecated DB instance classes, you can choose a DB instance class that is not deprecated when you restore the DB snapshots. For more information, see [Restoring to a DB instance](USER_RestoreFromSnapshot.md).