ApsaraDB RDS for PostgreSQL read-only instances are available in two editions and two resource models. Both subscription and pay-as-you-go billing are supported. For pricing details, see Read-only instance pricing.
Choose an instance type
Use the following table to select the right combination of edition and resource model for your workload.
| Edition | Resource model | Best for |
|---|---|---|
| Standard Edition | General-purpose | Development, testing, and read-heavy workloads where peak IOPS is not a hard requirement |
| Standard Edition | Dedicated | Production workloads that require guaranteed IOPS and I/O bandwidth |
| Yitian Edition | General-purpose | Development, testing, and read-heavy workloads on Alibaba Cloud's Yitian ARM-based processors |
| Yitian Edition | Dedicated | Production workloads that require guaranteed IOPS and benefit from the Yitian ARM architecture |
Standard Edition runs on x86 architecture. Yitian Edition runs on Alibaba Cloud's Yitian ARM-based processors. For a full comparison, see Product types.
Standard Edition instance types
General-purpose
Standard Edition instances run on x86 architecture and are available in General-purpose and Dedicated resource models.
General-purpose instances share physical CPU and memory resources with other instances on the same host. IOPS and I/O bandwidth are not guaranteed.
| Instance type code | CPU and memory | Maximum connections |
|---|---|---|
| pgro.n2.2c.1m | 2 cores, 4 GB | 400 |
| pgro.n4.2c.1m | 2 cores, 8 GB | 800 |
| pgro.n2.4c.1m | 4 cores, 8 GB | 800 |
| pgro.n4.4c.1m | 4 cores, 16 GB | 1,600 |
| pgro.n2.8c.1m | 8 cores, 16 GB | 1,600 |
| pgro.n4.8c.1m | 8 cores, 32 GB | 3,200 |
Dedicated
Dedicated instances reserve physical CPU and memory resources exclusively for a single instance, providing guaranteed IOPS and I/O bandwidth.
Due to product optimization and resource planning adjustments, some instance types will be discontinued. For details, see [Discontinued] Some ApsaraDB RDS for PostgreSQL instance types will stop being sold starting February 28, 2026.
| Instance type code | CPU and memory | Maximum connections | Maximum IOPS | Maximum I/O bandwidth (MB/s) |
|---|---|---|---|---|
| pgro.x2.medium.1c | 2 cores, 4 GB | 400 | 10,000 | 128 |
| pgro.x4.medium.1c | 2 cores, 8 GB | 800 | 10,000 | 128 |
| pgro.x8.medium.1c | 2 cores, 16 GB | 1,600 | 10,000 | 128 |
| pgro.x2.large.1c | 4 cores, 8 GB | 800 | 20,000 | 192 |
|
pgro.x2.16xlarge.1c |
128 cores, 256 GB |
25600 |
320000 |
2560 |
| pgro.x4.large.1c | 4 cores, 16 GB | 1,600 | 20,000 | 192 |
| pgro.x8.large.1c | 4 cores, 32 GB | 3,200 | 20,000 | 192 |
| pgro.x2.xlarge.1c | 8 cores, 16 GB | 1,600 | 25,000 | 256 |
| pgro.x4.xlarge.1c | 8 cores, 32 GB | 3,200 | 25,000 | 256 |
| pgro.x8.xlarge.1c | 8 cores, 64 GB | 6,400 | 25,000 | 256 |
| pgro.x2.3large.1c | 12 cores, 24 GB | 2,400 | 30,000 | 320 |
| pgro.x4.3large.1c | 12 cores, 48 GB | 4,800 | 30,000 | 320 |
| pgro.x8.3large.1c | 12 cores, 96 GB | 9,600 | 30,000 | 320 |
| pgro.x2.2xlarge.1c | 16 cores, 32 GB | 3,200 | 40,000 | 384 |
| pgro.x4.2xlarge.1c | 16 cores, 64 GB | 6,400 | 40,000 | 384 |
| pgro.x8.2xlarge.1c | 16 cores, 128 GB | 12,800 | 40,000 | 384 |
| pgro.x2.3xlarge.1c | 24 cores, 48 GB | 4,800 | 50,000 | 512 |
| pgro.x4.3xlarge.1c | 24 cores, 96 GB | 9,600 | 50,000 | 512 |
| pgro.x8.3xlarge.1c | 24 cores, 192 GB | 19,200 | 50,000 | 512 |
| pgro.x2.4xlarge.1c | 32 cores, 64 GB | 6,400 | 60,000 | 640 |
| pgro.x4.4xlarge.1c | 32 cores, 128 GB | 12,800 | 60,000 | 640 |
| pgro.x8.4xlarge.1c | 32 cores, 256 GB | 25,600 | 60,000 | 640 |
| pgro.x2.13large.1c | 52 cores, 96 GB | 9,600 | 100,000 | 1,024 |
| pgro.x4.13large.1c | 52 cores, 192 GB | 19,200 | 100,000 | 1,024 |
| pgro.x8.13large.1c | 52 cores, 384 GB | 38,400 | 100,000 | 1,024 |
| pgro.x2.8xlarge.1c | 64 cores, 128 GB | 12,800 | 120,000 | 1,280 |
| pgro.x4.8xlarge.1c | 64 cores, 256 GB | 25,600 | 120,000 | 1,280 |
| pgro.x8.8xlarge.1c | 64 cores, 512 GB | 51,200 | 120,000 | 1,280 |
| pgro.x2.12xlarge.1c | 96 cores, 192 GB | 19,200 | 240,000 | 2,048 |
| pgro.x4.12xlarge.1c | 96 cores, 384 GB | 38,400 | 240,000 | 2,048 |
| pgro.x8.12xlarge.1c | 96 cores, 768 GB | 76,800 | 240,000 | 2,048 |
| pgro.x2.13xlarge.1c | 104 cores, 192 GB | 19,200 | 200,000 | 2,048 |
| pgro.x4.13xlarge.1c | 104 cores, 384 GB | 38,400 | 200,000 | 2,048 |
| pgro.x8.13xlarge.1c | 104 cores, 768 GB | 76,800 | 200,000 | 2,048 |
| pgro.x2.16xlarge.1c | 128 cores, 256 GB | 25,600 | 320,000 | 2,560 |
| pgro.x4.16xlarge.1c | 128 cores, 512 GB | 51,200 | 320,000 | 2,560 |
| pgro.x8.16xlarge.1c | 128 cores, 1,024 GB | 102,400 | 320,000 | 2,560 |
| pgro.x2.24xlarge.1c | 192 cores, 384 GB | 38,400 | 500,000 | 4,096 |
| pgro.x4.24xlarge.1c | 192 cores, 768 GB | 76,800 | 500,000 | 4,096 |
| pgro.x8.24xlarge.1c | 192 cores, 1,536 GB | 153,600 | 500,000 | 4,096 |
Yitian Edition instance types
General-purpose
Yitian Edition instances run on Alibaba Cloud's Yitian ARM-based processors. General-purpose and Dedicated models follow the same resource allocation rules as their Standard Edition counterparts.
General-purpose instances share physical CPU and memory resources with other instances on the same host. IOPS and I/O bandwidth are not guaranteed.
| Instance type code | CPU and memory | Maximum connections |
|---|---|---|
| pgro.n2m.2c.1m | 2 cores, 4 GB | 400 |
| pgro.n2m.4c.1m | 4 cores, 8 GB | 800 |
| pgro.n2m.8c.1m | 8 cores, 16 GB | 1,600 |
| pgro.n4m.2c.1m | 2 cores, 8 GB | 800 |
| pgro.n4m.4c.1m | 4 cores, 16 GB | 1,600 |
| pgro.n4m.8c.1m | 8 cores, 32 GB | 3,200 |
Dedicated
Dedicated instances reserve physical CPU and memory resources exclusively for a single instance, providing guaranteed IOPS and I/O bandwidth.
| Instance type code | CPU and memory | Maximum connections | Maximum IOPS | Maximum I/O bandwidth (MB/s) |
|---|---|---|---|---|
| pgro.x2m.medium.1c | 2 cores, 4 GB | 400 | 20,000 | 192 |
| pgro.x2m.large.1c | 4 cores, 8 GB | 800 | 40,000 | 256 |
| pgro.x2m.xlarge.1c | 8 cores, 16 GB | 1,600 | 50,000 | 384 |
| pgro.x2m.2xlarge.1c | 16 cores, 32 GB | 3,200 | 80,000 | 640 |
| pgro.x2m.4xlarge.1c | 32 cores, 64 GB | 6,400 | 125,000 | 1,024 |
| pgro.x2m.8xlarge.1c | 64 cores, 128 GB | 12,800 | 250,000 | 2,048 |
| pgro.x4m.medium.1c | 2 cores, 8 GB | 800 | 20,000 | 192 |
| pgro.x4m.large.1c | 4 cores, 16 GB | 1,600 | 40,000 | 256 |
| pgro.x4m.xlarge.1c | 8 cores, 32 GB | 3,200 | 50,000 | 384 |
| pgro.x4m.2xlarge.1c | 16 cores, 64 GB | 6,400 | 80,000 | 640 |
| pgro.x4m.4xlarge.1c | 32 cores, 128 GB | 12,800 | 125,000 | 1,024 |
| pgro.x4m.8xlarge.1c | 64 cores, 256 GB | 25,600 | 250,000 | 2,048 |
| pgro.x8m.medium.1c | 2 cores, 16 GB | 1,600 | 20,000 | 192 |
| pgro.x8m.large.1c | 4 cores, 32 GB | 3,200 | 40,000 | 256 |
| pgro.x8m.xlarge.1c | 8 cores, 64 GB | 6,400 | 50,000 | 384 |
| pgro.x8m.2xlarge.1c | 16 cores, 128 GB | 12,800 | 80,000 | 640 |
| pgro.x8m.4xlarge.1c | 32 cores, 256 GB | 25,600 | 125,000 | 1,024 |
| pgro.x8m.8xlarge.1c | 64 cores, 512 GB | 51,200 | 250,000 | 2,048 |
High-availability series instance types
High-availability series read-only instance types are available only for the Standard Edition.
Dedicated
|
Instance type code |
CPU and memory |
Maximum connections |
Maximum IOPS |
Maximum I/O bandwidth (MB/s) |
Storage space |
|
pgro.x2.medium.2c |
2 cores, 4 GB |
400 |
10000 |
128 |
|
|
pgro.x4.medium.2c |
2 cores, 8 GB |
800 |
10000 |
128 |
|
|
pgro.x8.medium.2c |
2 cores, 16 GB |
1600 |
10000 |
128 |
|
|
pgro.x2.large.2c |
4 cores, 8 GB |
800 |
20000 |
192 |
|
|
pgro.x4.large.2c |
4 cores, 16 GB |
1600 |
20000 |
192 |
|
|
pgro.x8.large.2c |
4 cores, 32 GB |
3200 |
20000 |
192 |
|
|
pgro.x2.xlarge.2c |
8 cores, 16 GB |
1600 |
25000 |
256 |
|
|
pgro.x4.xlarge.2c |
8 cores, 32 GB |
3200 |
25000 |
256 |
|
|
pgro.x8.xlarge.2c |
8 cores, 64 GB |
6400 |
25000 |
256 |
|
|
pgro.x2.2xlarge.2c |
16 cores, 32 GB |
3200 |
40000 |
384 |
|
|
pgro.x4.2xlarge.2c |
16 cores, 64 GB |
6400 |
40000 |
384 |
|
|
pgro.x8.2xlarge.2c |
16 cores, 128 GB |
12800 |
40000 |
384 |
|
|
pgro.x4.3xlarge.2c |
24 cores, 96 GB |
9600 |
50000 |
512 |
|
|
pgro.x2.4xlarge.2c |
32 cores, 64 GB |
6400 |
60000 |
640 |
|
|
pgro.x4.4xlarge.2c |
32 cores, 128 GB |
12800 |
60000 |
640 |
|
|
pgro.x8.4xlarge.2c |
32 cores, 256 GB |
25600 |
60000 |
640 |
|
|
pgro.x2.8xlarge.2c |
64 cores, 128 GB |
12800 |
120000 |
1280 |
|
|
pgro.x4.8xlarge.2c |
64 cores, 256 GB |
25600 |
120000 |
1280 |
|
|
pgro.x8.8xlarge.2c |
64 cores, 512 GB |
51200 |
120000 |
1280 |
|
|
pgro.x2.16xlarge.2c |
128 cores, 256 GB |
25600 |
200000 |
2048 |
|
|
pgro.x4.16xlarge.2c |
128 cores, 512 GB |
51200 |
200000 |
2048 |
|
|
pgro.x8.16xlarge.2c |
128 cores, 1024 GB |
102400 |
200000 |
2048 |
Before you read the tables
-
Maximum IOPS and maximum I/O bandwidth: Actual values are affected by the storage class, storage capacity, and instance type. See Maximum IOPS formula and Maximum throughput formula for the calculation details.
-
General-purpose IOPS: IOPS and I/O bandwidth are not guaranteed on General-purpose instances because physical resources are shared across multiple instances on the same host. If your workload is sensitive to IOPS, use a Dedicated instance type.
-
Storage options: All current instance types support the following storage classes: PL1 ESSD (20 GB–64,000 GB), PL2 ESSD (500 GB–64,000 GB), PL3 ESSD (1,500 GB–64,000 GB), and premium performance disk (10 GB–64,000 GB).
Legacy instance types
The following instance types are no longer available for purchase. Migrate to the current instance types listed above.
| Instance type code | CPU | Memory | Maximum connections | Maximum IOPS |
|---|---|---|---|---|
| pgro.n2.small.1c | 1 core | 2 GB | 200 | See List of read-only instance types |
| pgro.n2.medium.1c | 2 cores | 4 GB | 400 | See List of read-only instance types |
| pg.x8.xlarge.2 | 8 cores | 64 GB | 10,000 | 18,000 |
| pg.x8.2xlarge.2 | 16 cores | 128 GB | 12,000 | 36,000 |
| pg.x4.xlarge.2 | 8 cores | 32 GB | 5,000 | 9,000 |
| pg.x4.2xlarge.2 | 16 cores | 64 GB | 10,000 | 18,000 |
| pg.x4.4xlarge.2 | 32 cores | 128 GB | 12,000 | 36,000 |
| rds.pg.st.h43 | 60 cores | 470 GB | 4,000 | 50,000 |