This topic provides general information about Alibaba Cloud enhanced SSDs (ESSDs), such as performance levels (PLs), usage scenarios, and performance specifications. ESSDs integrate 25 Gigabit Ethernet and remote direct memory access (RDMA) technologies to reduce latency and deliver up to 1 million random IOPS.

Specifications

Note PL0 ESSDs have been put into public preview. You cannot modify the PL of PL0 ESSDs during the public preview.

The API parameter value cloud_essd indicates ESSDs. ESSDs are divided into four PLs based on the maximum performance per disk.

Property of ESSD PL
PL3 PL2 PL1 PL0
Performance description Ultra high maximum concurrent I/O performance and ultra low I/O latency High maximum concurrent I/O performance and low I/O latency Moderate maximum concurrent I/O performance and low I/O latency Moderate maximum concurrent I/O performance and low I/O latency
Capacity (GiB) 1,261‒32,768 461‒32,768 20‒32,768 40‒32,768
Data durability 99.9999999% 99.9999999% 99.9999999% 99.9999999%
Maximum input/output operations per second (IOPS) per disk 1,000,000 100,000 50,000 10,000
Maximum throughput per disk (MB/s) 4,000 750 350 180
Formula for calculating the IOPS per disk min{1,800 + 50 × Capacity, 1,000,000} min{1,800 + 50 × Capacity, 100,000} min{1,800 + 50 × Capacity, 50,000} min{1,800 + 12 × Capacity, 10,000}
Formula for calculating the throughput per disk (MB/s) min{120 + 0.5 × Capacity, 4,000} min{120 + 0.5 × Capacity, 750} min{120 + 0.5 × Capacity, 350} min{100 + 0.25 × Capacity, 180}
Example scenario Large and medium-sized relational databases for core businesses and NoSQL databases, and large SAP and Oracle databases Medium-sized relational databases and NoSQL databases, medium-sized ELK log clusters, and enterprise-level commercial software such as SAP and Oracle Small and medium-sized MySQL and SQL Server databases, small and medium-sized ELK log clusters, enterprise-level commercial software such as SAP and Oracle, and container applications Small and medium-sized MySQL and SQL Server databases, small and medium-sized ELK log clusters, enterprise-level commercial software such as SAP and Oracle, and container applications
System or data disks that are recommended to be replaced with ESSDs in recommended business scenarios Data disks of instance families with local SSDs and 16 or more vCPUs (i1, i2, and i2g) Data disks of instance families with local SSDs (i1, i2, and i2g) Standard SSDs System disks

For information about how to perform stress testing on ESSDs, see Test the IOPS performance of an enhanced SSD.

Billing methods

ESSDs support pay-as-you-go and subscription billing methods. For more information, see Create a pay-as-you-go disk and Create a subscription disk.

For information about the pricing of ESSDs at different PLs, see the Pricing tab on the Elastic Compute Service page.

Scenarios

ESSDs are suitable for the following latency-sensitive applications or I/O intensive business scenarios:

  • Large online transaction processing (OLTP) databases: relational databases such as MySQL, PostgreSQL, Oracle, and SQL Server databases
  • NoSQL databases: non-relational databases such as MongoDB, HBase, and Cassandra databases
  • Elasticsearch distributed logs: Elasticsearch, Logstash, and Kibana (ELK) log analysis

Capacity and PLs of ESSDs

The performance of a storage device is closely related to the capacity of the device. A storage device with larger capacity provides higher data processing capabilities. All ESSDs have the same I/O performance per unit capacity. However, the performance of ESSDs increases linearly with its capacity until the maximum performance per disk at the PL is reached.
PL Capacity of ESSD (GiB) Maximum IOPS Maximum throughput (Mbit/s)
PL0 40‒32,768 10,000 180
PL1 20‒32,768 50,000 350
PL2 461‒32,768 100,000 750
PL3 1,261‒32,768 1,000,000 4,000
  • Example 1: If Alex selects 20 GiB of storage capacity when he creates an ESSD in the ECS console, PL1 is the only available option. PL1 ESSDs have a maximum IOPS of 50,000.Create an ESSD in the ECS console
  • Example 2: If Alex selects 32,000 GiB of storage capacity when he creates an ESSD in the ECS console, all PLs are available. The maximum IOPS for PL0 is 10,000, PL1 is 50,000, PL2 is 100,000, and PL3 is 1,000,000.Create an ESSD in the ECS console

Storage I/O performance of instance types

The storage I/O performance of some new-generation instance families is proportional to the specifications of instance types. For example, in the g5se storage enhanced instance family, the higher the specification an instance type has, the higher storage IOPS and throughput it can deliver. For more information, see Storage I/O performance.

The following section describes the relationship between instance types and performance of ESSDs:

  • If the total storage performance of ESSDs does not exceed the maximum storage performance that the instance type can deliver, the instance delivers the total storage performance of the ESSDs.
  • If the total storage performance of ESSDs exceeds the maximum storage performance that the instance type can deliver, the storage performance of the instance is limited to the maximum storage performance that the instance type can deliver.

The actual storage performance differs among g5se instances of different instance types that have ESSDs at different PLs attached:

  • Example 1: Alex creates a 16 GiB instance of the ecs.g5se.xlarge instance type. The maximum IOPS of this instance type is 60,000. Alex then attaches to the instance a PL2 ESSD whose capacity is 2,000 GiB and maximum IOPS is 100,000. The maximum IOPS of the instance is limited by the maximum IOPS of the instance type to 60,000.
  • Example 2: Alex creates a 64 GiB instance of the ecs.g5se.4xlarge instance type. The maximum IOPS of this instance type is 230,000. Alex then attaches to the instance three PL2 ESSDs. Each ESSD has a capacity of 2,000 GiB and a maximum IOPS of 100,000. The total maximum IOPS of these ESSDs is 300,000. The maximum IOPS of the instance is limited by the maximum IOPS of the instance type to 230,000.
  • Example 3: Alex creates a 64 GiB instance of the ecs.g5se.4xlarge instance type. The maximum IOPS of this instance type is 230,000. Alex then attaches to the instance a PL3 ESSD whose capacity is 2,000 GiB and maximum IOPS is 101,800. The maximum IOPS of the instance is no longer limited by the maximum IOPS of the instance type, but is limited by the maximum IOPS of the ESSD to 101,800.

Instance families supported by ESSDs

The instance families supported by ESSDs, see Instance families.