Alibaba Cloud provides enhanced SSDs (ESSDs) at different performance levels (PLs). The ESSDs of PL1 are designed based on a new generation of distributed block storage architecture. ESSDs require the same price as standard SSDs in most regions, but deliver higher IOPS, higher throughput, and more stable I/O performance than standard SSDs. From July 01, 2022, Alibaba Cloud gradually phases out the standard SSD storage type for specific database engines in ApsaraDB RDS. This makes it easier to select the storage type for an ApsaraDB RDS instance.

Specific database engines and end-of-sale dates

Database engine End-of-sale date
MySQL July 01, 2022
MariaDB TX July 01, 2022
PostgreSQL July 06, 2022
SQL Server July 08, 2022
Note You cannot select the standard SSD storage type when you create an ApsaraDB RDS for MySQL instance, ApsaraDB RDS for MariaDB TX instance, ApsaraDB RDS for PostgreSQL instance, or ApsaraDB RDS for SQL Server instance. You can still select the local SSD storage type for the RDS instance.

Impacts and suggestions

Performance comparison between ESSDs of PL1 and standard SSDs

ESSDs of PL1 require the same price as standard SSDs in most regions but deliver higher performance. The following table describes the specific performance differences.

Item ESSD of PL1 Standard SSD
Maximum capacity of a single SSD (GiB) 20 to 32,768 32,768
Maximum IOPS 50,000 25,000
Maximum throughput (MB/s) 350 300
IOPS per SSD min{1,800 + 50 × Capacity, 50,000} min{1,800 + 30 × Capacity, 25,000}
Throughput per SSD (MB/s) min{120 + 0.5 × Capacity, 350} min{120 + 0.5 × Capacity, 300}
Average random write latency per connection (ms) 0.2 0.5 to 2