This topic provides general information about Alibaba Cloud enhanced SSDs (ESSDs), such as performance levels, usage scenarios, and performance specifications. ESSDs are provisioned on a 25GE network and based on the remote direct memory access (RDMA) technology. Each ESSD can deliver up to 1,000,000 random IOPS with low latency.

Scenarios

Enhanced SSDs feature low latency, fast response, and high data throughput. They are ideal for latency-sensitive applications or I/O intensive business scenarios, for example:

  • 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
  • Real-time analysis applications: Elasticsearch distributed log analysis, Elasticsearch, Logstash, and Kibana (ELK) log analysis

Specifications

The API parameter value cloud_essd indicates ESSDs. ESSDs are divided into three performance levels (PLs) based on the maximum performance per disk.

Property of ESSDs Performance level 3 Performance level 2 Performance level 1
PL PL3 PL2 PL1
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
Capacity (GiB) 1,261~32,768 461~32,768 20~32,768
Data reliability 99.9999999% 99.9999999% 99.9999999%
Maximum input/output operations per second (IOPS) per disk 1,000,000 100,000 50,000
Maximum throughput per disk (MB/s) 4,000 750 350
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}
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}
Products where ESSDs are recommended to be used or disks that can be replaced with ESSDs Instance families with local SSDs and 16 or more vCPUs (i1, i2, and i2g) Instance families with local SSDs (i1, i2, and i2g) Standard SSDs and ultra disks
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

Billing methods

Enhanced SSDs 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 performance levels, click the Pricing tab of the Elastic Compute Service page.

Capacity and performance levels 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 for that performance level is reached.
Performance level Capacity of ESSDs (GiB) Maximum IOPS Maximum throughput (MB/s)
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 ESSD in the ECS console, PL1 is the only available option. Each PL1 ESSD has a maximum IOPS of 50,000.Create an ESSD in the ECS console
  • Example 2: If Alex selects 32,000 GiB of storage capacity, PL1-PL3 levels are available. The maximum IOPS for 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 instance specifications.

The following examples show you how instance types and performance specifications of attached ESSDs determine the maximum IOPS of instances.

  • 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 an ESSD whose capacity is 1,800 GiB and maximum IOPS is 100,000. The 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 an ESSD whose capacity is 1,800 GiB and maximum IOPS is 100,000. The maximum IOPS of the instance is 100,000, because it is no longer limited by the maximum IOPS of the instance type, but is instead limited by the maximum IOPS of the ESSD.

Related operations

Business need Documentation Related API operation
Create an ESSD separately and use it as a data disk CreateDisk
Change billing methods Convert the billing method of a cloud disk ModifyDiskChargeType
Attach a pay-as-you-go data disk to an ECS instance Attach a data disk AttachDisk
Create a normal or local snapshot Create a normal snapshot CreateSnapshot
Increase the capacity of an ESSD Overview ResizeDisk
Resize an ESSD to improve performance
Detach a pay-as-you-go data disk Detach a data disk DetachDisk
Release a data disk separately Release a disk DeleteDisk