x86-based Instance Classes

To learn about the DB engine versions supported by RDS for PostgreSQL, see DB Engines and Versions.

RDS for PostgreSQL supports the following x86-based instance classes: general-purpose (recommended), dedicated (recommended), general-enhanced (installed base operations), and general-enhanced II (installed base operations), as listed in Table 1. For details about each instance class, see Table 2 and Table 3.

**Table 1** x86-based instance classes
Instance Class	Description	Scenario	Constraints
General-purpose (recommended)	CPU resources are shared with other general-purpose DB instances on the same physical machine. CPU usage is maximized through resource overcommitment. This instance class is a cost-effective option and suitable for scenarios where performance stability is not critical.	Suitable for scenarios that have high requirements on cost-effectiveness.	These instance classes are available in the following regions: CN North-Beijing4 and CN North-Ulanqab1 CN East-Shanghai1 CN South-Guangzhou and CN South-Guangzhou-InvitationOnly CN Southwest-Guiyang1 AP-Bangkok and AP-Singapore CN-Hong Kong LA-Sao Paulo1, LA-Santiago, LA-Mexico City1, and LA-Mexico City2 AF-Johannesburg
Dedicated (recommended)	The instance has dedicated CPU and memory resources to ensure stable performance. The performance of a dedicated instance is never affected by other instances on the same physical machine. This instance class is good when performance stability is important.	Suitable for core database scenarios such as e-commerce, gaming, finance, government, and enterprise applications.
General-enhanced and general-enhanced II	With a leading network acceleration engine and Data Plane Development Kit (DPDK) fast packet processing, this instance class provides higher network performance and computing power.	Suitable for websites and web applications that require high database computing and network performance.	These two instance classes are for installed base operations.

**Table 2** Details of general-purpose and dedicated instance classes
Instance Class	Specification Code for Primary/Standby Instances	Specification Code for Read Replicas	Specification Code for Single-Node Instances	vCPUs	Memory (GB)
General-purpose	rds.pg.n1.medium.2.ha	rds.pg.n1.medium.2.rr	rds.pg.n1.medium.2	1	2
	rds.pg.n1.large.2.ha	rds.pg.n1.large.2.rr	rds.pg.n1.large.2	2	4
	rds.pg.n1.large.4.ha	rds.pg.n1.large.4.rr	rds.pg.n1.large.4	2	8
	rds.pg.n1.xlarge.2.ha	rds.pg.n1.xlarge.2.rr	rds.pg.n1.xlarge.2	4	8
	rds.pg.n1.xlarge.4.ha	rds.pg.n1.xlarge.4.rr	rds.pg.n1.xlarge.4	4	16
	rds.pg.n1.2xlarge.2.ha	rds.pg.n1.2xlarge.2.rr	rds.pg.n1.2xlarge.2	8	16
	rds.pg.n1.2xlarge.4.ha	rds.pg.n1.2xlarge.4.rr	rds.pg.n1.2xlarge.4	8	32
Dedicated NOTE: The specifications supported for cloud SSDs and extreme SSDs are different.	rds.pg.x1.large.2.ha	rds.pg.x1.large.2.rr	-	2	4
	rds.pg.x1.large.4.ha	rds.pg.x1.large.4.rr	-	2	8
	rds.pg.x1.large.8.ha	rds.pg.x1.large.8.rr	-	2	16
	rds.pg.x1.xlarge.2.ha	rds.pg.x1.xlarge.2.rr	-	4	8
	rds.pg.x1.xlarge.4.ha	rds.pg.x1.xlarge.4.rr	-	4	16
	rds.pg.x1.xlarge.8.ha	rds.pg.x1.xlarge.8.rr	rds.pg.x1.xlarge.8	4	32
	rds.pg.x1.2xlarge.2.ha	rds.pg.x1.2xlarge.2.rr	rds.pg.x1.2xlarge.2	8	16
	rds.pg.x1.2xlarge.4.ha	rds.pg.x1.2xlarge.4.rr	rds.pg.x1.2xlarge.4	8	32
	rds.pg.x1.2xlarge.8.ha	rds.pg.x1.2xlarge.8.rr	rds.pg.x1.2xlarge.8	8	64
	rds.pg.x1.2xlarge.16.ha	rds.pg.x1.2xlarge.16.rr	rds.pg.x1.2xlarge.16	8	128
	rds.pg.x1.4xlarge.2.ha	rds.pg.x1.4xlarge.2.rr	rds.pg.x1.4xlarge.2	16	32
	rds.pg.x1.4xlarge.4.ha	rds.pg.x1.4xlarge.4.rr	rds.pg.x1.4xlarge.4	16	64
	rds.pg.x1.4xlarge.8.ha	rds.pg.x1.4xlarge.8.rr	rds.pg.x1.4xlarge.8	16	128
	rds.pg.x1.8xlarge.2.ha	rds.pg.x1.8xlarge.2.rr	rds.pg.x1.8xlarge.2	32	64
	rds.pg.x1.8xlarge.4.ha	rds.pg.x1.8xlarge.4.rr	rds.pg.x1.8xlarge.4	32	128
	rds.pg.x1.8xlarge.8.ha	rds.pg.x1.8xlarge.8.rr	rds.pg.x1.8xlarge.8	32	256
	rds.pg.x1.16xlarge.2.ha	rds.pg.x1.16xlarge.2.rr	rds.pg.x1.16xlarge.2	64	128
	rds.pg.x1.16xlarge.4.ha	rds.pg.x1.16xlarge.4.rr	rds.pg.x1.16xlarge.4	64	256
	rds.pg.x1.16xlarge.8.ha	rds.pg.x1.16xlarge.8.rr	rds.pg.x1.16xlarge.8	64	512