Measure the performance metrics and specifications of block storage devices - Elastic Compute Service

Various block storage devices, such as cloud disks and local disks, have different performance metrics and specifications. Familiarize yourself with performance metrics and select block storage devices that are suitable for specific workloads and applications based on your storage capacity requirements and the performance metrics. This topic describes the performance metrics and specifications of cloud disks and local disks.

Performance metrics

The key metrics that are used to measure the performance of block storage devices include IOPS, throughput, and latency. Specific block storage devices have capacity requirements. For example, enhanced SSDs (ESSDs) at different performance levels (PLs) have different capacity ranges.

IOPS

IOPS measures the number of read/write operations that can be performed per second. High IOPS is critical for transaction-intensive applications such as database applications. A standard SSD can deliver the maximum IOPS only when the standard SSD is attached to an I/O optimized Elastic Compute Service (ECS) instance. For information about ECS instances of which instance families are I/O optimized instances, see Overview of instance families. The following table describes the common IOPS metrics.

Metric	Description	Data access method
Total IOPS	The total number of I/O operations per second.	Access locations on storage devices in a continuous or non-continuous manner.
Random read IOPS	The average number of random read I/O operations per second.	Access locations on storage devices in a non-continuous manner.
Random write IOPS	The average number of random write I/O operations per second.
Sequential read IOPS	The average number of sequential read I/O operations per second.	Access locations on storage devices in a continuous manner.
Sequential write IOPS	The average number of sequential write I/O operations per second.	Access locations on storage devices in a continuous manner.

Throughput
Throughput measures the amount of data that is transferred per second. Unit: MB/s. High throughput is critical for applications such as Hadoop offline computing applications that require a large number of sequential read/write operations.
Latency
Latency measures the amount of time that is required for a block storage device to process an I/O request. Unit: seconds, milliseconds, or microseconds. High latency may cause performance to degrade or lead to errors in applications that require low latency.
- For latency-sensitive applications such as database applications, we recommend that you use ESSD AutoPL disks, ESSDs, standard SSDs, or local SSDs.
- For latency-insensitive applications that require high throughput such as Hadoop offline computing applications, we recommend that you use ECS instances of the d1 or d1ne instance family to which local SATA HDDs are attached.
Capacity
Capacity is the amount of storage space. Unit: TiB, GiB, MiB, or KiB. Block storage capacity is measured in binary units. For example, 1 GiB equals 1,024 MiB.
You cannot use capacity as a metric to measure the performance of block storage devices, but the performance of block storage devices varies based on the capacity of the devices. A block storage device that has a larger capacity provides stronger processing capabilities. Block storage devices of the same category have the same I/O performance per unit capacity. However, the performance of a cloud disk linearly increases together with the disk capacity up to the single-disk maximum performance of the disk category. ESSDs in different capacity ranges have different PLs.

For information about how to test the performance of different categories of block storage devices, see Test the performance of block storage devices, Test the IOPS performance of an ESSD, and Test the performance of local disks on an i4p instance.

Performance of cloud disks

The following table describes the performance and common usage scenarios of different categories of cloud disks.

Note

Standard SSDs, ultra disks, and basic disks are cloud disks of the previous generation and no longer available for purchase in specific regions and zones. We recommend that you use ESSDs at PL 0 (PL0 ESSDs) or ESSD Entry disks instead of ultra disks and basic disks and use ESSD AutoPL disks instead of standard SSDs.

Item	ESSD AutoPL disk	ESSD				ESSD Entry disk	Standard SSD	Ultra disk	Basic disk
PL	An ESSD AutoPL disk can decouple capacity from performance and deliver baseline performance that is equal to the baseline performance of an ESSD PL1 disk. You can configure provisioned performance and burst performance for ESSD AutoPL disks.	PL3	PL2	PL1	PL0	None	None	None	None
Single-disk capacity range (GiB)	1 to 65,536	1,261 to 65,536	461 to 65,536	20 to 65,536	1 to 65,536	10 to 32,768	20 to 32,768	20 to 32,768	5 to 2,000
Max IOPS/Min IOPS	1,000,000/3,000	1,000,000/64,850	100,000/24,872	50,000/2,800	10,000/1,812	6,000/1,880	25,000/2,400 ^②	5,000/1,960	Hundreds
Max throughput/Min throughput (MB/s)	4,096/125	4,000/750.5	750/350.5	350/130	180/100	150/101.5	300/130 ^②	140/103	30 to 40
Formula for calculating single-disk IOPS^①	Baseline performance: max{min{1,800 + 50 × Capacity, 50,000}, 3,000} Provisioned performance: min{Provisioned IOPS, 50,000} Burst performance: min{IOPS supported by the instance type, 1,000,000}	min{1,800 + 50 × Capacity, 1,000,000}	min{1,800 + 50 × Capacity, 100,000}	min{1800 + 50 × Capacity, 50,000}	min{1,800+12 × Capacity, 10,000}	min{1,800 + 8 × Capacity, 6,000}	min{1,800 + 30 × Capacity, 25,000}	min{1,800 + 8 × Capacity, 5,000}	None
Formula for calculating single-disk throughput (MB/s) ^①	Baseline performance: max{min{120 + 0.5 × Capacity, 350}, 125} Provisioned performance: min{16 KB × Provisioned IOPS/1,024, Maximum throughput per disk} Burst performance: min{Throughout supported by the instance type, 4 GB/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}	min{100 + 0.15 × Capacity, 150}	min{120 + 0.5 × Capacity, 300}	min{100 + 0.15 × Capacity, 140}	None
Data durability	99.9999999%	99.9999999%	99.9999999%	99.9999999%	99.9999999%	99.9999999%	99.9999999%	99.9999999%	99.9999999%
Average one-way random write latency in milliseconds (block size = 4 KB)	0.2	0.2	0.2	0.2	0.3 to 0.5	1 to 3	0.5 to 2	1 to 3	5 to 10

^① In the following examples, a PL0 ESSD is used to describe how to calculate single-disk performance:
- Single-disk maximum IOPS: The baseline IOPS is 1,800 and increases by 12 per additional GiB to up to 10,000.
- Single-disk maximum throughput: The baseline throughput is 100 MB/s and increases by 0.25 MB/s per additional GiB to up to 180 MB/s.
^② The performance of standard SSDs varies based on the size of data blocks. Standard SSDs that contain smaller data blocks deliver lower throughput and higher IOPS. The following table provides a comparison of data blocks.
Data block size (KiB)
Maximum IOPS
Throughput
4
Approximately 25,000
Approximately 100
16
Approximately 17,200
Approximately 260
32
Approximately 9,600
Approximately 300
64
Approximately 4,800
Approximately 300

Performance of local disks

Local NVMe SSDs

The following table describes the performance metrics of local NVMe SSDs that the d3c instance family uses.

Metric	Single-disk performance	ecs.d3c.3xlarge	ecs.d3c.7xlarge	ecs.d3c.14xlarge
Maximum read IOPS	100,000	100,000	200,000	400,000
Maximum read throughput	4 GB/s	4 GB/s	8 GB/s	16 GB/s
Maximum write throughput	2 GB/s	2 GB/s	4 GB/s	8 GB/s

The following table describes the performance metrics of the local NVMe SSDs that the i4 instance family uses.

Metric	ecs.i4.large	ecs.i4.xlarge	ecs.i4.2xlarge	ecs.i4.4xlarge	ecs.i4.8xlarge	ecs.i4.16xlarge	ecs.i4.32xlarge
Maximum read IOPS	112,500	225,000	450,000	900,000	1,800,000	3,600,000	7,200,000
Maximum read throughput	0.75 GB/s	1.5 GB/s	3 GB/s	6 GB/s	12 GB/s	24 GB/s	48 GB/s
Maximum write throughput	0.375 GB/s	0.75 GB/s	1.5 GB/s	3 GB/s	6 GB/s	12 GB/s	24 GB/s

Note

The performance data in the preceding table represents the highest performance levels of local storage in the instance families. The instance families support only Linux images. We recommend that you use the most recent Linux image versions, such as Alibaba Cloud Linux 3, to obtain optimal performance.

The following table describes the performance metrics of the local NVMe SSDs that the i4g and i4r instance families use.

Metric	ecs.i4g.4xlarge and ecs.i4r.4xlarge	ecs.i4g.8xlarge and ecs.i4r.8xlarge	ecs.i4g.16xlarge and ecs.i4r.16xlarge	ecs.i4g.32xlarge and ecs.i4r.32xlarge
Maximum read IOPS	250,000	500,000	1,000,000	2,000,000
Maximum read throughput	1.5 GB/s	3 GB/s	6 GB/s	12 GB/s
Maximum write throughput	1 GB/s	2 GB/s	4 GB/s	8 GB/s

Note

The performance data in the preceding table represents the highest performance levels of local storage for the instance families. The instance families support only Linux images. We recommend that you use the most recent Linux image versions, such as Alibaba Cloud Linux 3, to obtain optimal performance.

The following table describes the performance metrics of the local NVMe SSDs that the i3 instance family uses.

Metric	ecs.i3.xlarge	ecs.i3.2xlarge	ecs.i3.4xlarge	ecs.i3.8xlarge	ecs.i3.13xlarge	ecs.i3.26xlarge
Maximum read IOPS	250,000	500,000	1,000,000	2,000,000	3,000,000	6,000,000
Maximum read throughput	1.5 GB/s	3 GB/s	6 GB/s	12 GB/s	18 GB/s	36 GB/s
Maximum write throughput	1 GB/s	2 GB/s	4 GB/s	8 GB/s	12 GB/s	24 GB/s

Note

The following table describes the performance metrics of the local NVMe SSDs that the i3g instance family uses.

Metric	ecs.i3g.2xlarge	ecs.i3g.4xlarge	ecs.i3g.8xlarge	ecs.i3g.13xlarge	ecs.i3g.26xlarge
Maximum read IOPS	125,000	250,000	500,000	750,000	1,500,000
Maximum read throughput	0.75 GB/s	1.5 GB/s	3 GB/s	4.5 GB/s	9 GB/s
Maximum write throughput	0.5 GB/s	1 GB/s	2 GB/s	3 GB/s	6 GB/s

Note

The following table describes the performance metrics of the local NVMe SSDs that the i2 and i2g instance families use.

Metric	Single-disk performance		Overall instance performance^①
Metric	ecs.i2.xlarge and ecs.i2g.2xlarge	Other i2 and i2g instance types	Overall instance performance^①
Maximum capacity	894 GiB	1,788 GiB	8*1,788 GiB
Maximum read IOPS	150,000	300,000	1,500,000
Maximum read throughput	1 GB/s	2 GB/s	16 GB/s
Maximum write throughput	0.5 GB/s	1 GB/s	8 GB/s
Access latency	Several microseconds

^① Overall instance performance data in the preceding table applies only to the ecs.i2.16xlarge instance type and represents the highest performance levels of local storage in the i2 instance family.

The following table describes the performance metrics of the local NVMe SSDs that the i2ne and i2gne instance families use.

Metric	ecs.i2ne.xlarge and ecs.i2gne.2xlarge	ecs.i2ne.2xlarge and ecs.i2gne.4xlarge	ecs.i2ne.4xlarge and ecs.i2gne.8xlarge	ecs.i2ne.8xlarge and ecs.i2gne.16xlarge	ecs.i2ne.16xlarge
Maximum capacity	894 GiB	1,788 GiB	2*1,788 GiB	4*1,788 GiB	8*1,788 GiB
Maximum read IOPS	250,000	500,000	1,000,000	2,000,000	4,000,000
Maximum read throughput	1.5 GB/s	3 GB/s	6 GB/s	12 GB/s	24 GB/s
Maximum write throughput	1 GB/s	2 GB/s	4 GB/s	8 GB/s	16 GB/s
Access latency	Several microseconds

The following table describes the performance metrics of the local NVMe SSDs that the i1 instance family uses.

Metric	Single-disk performance	Overall instance performance^②
Maximum capacity	1,456 GiB	2,912 GiB
Maximum IOPS	240,000	480,000
Write IOPS^①	min{165 × Capacity, 240,000}	2 × min{165 × Capacity, 240,000}
Read IOPS^①	min{165 × Capacity, 240,000}	2 × min{165 × Capacity, 240,000}
Maximum read throughput	2 GB/s	4 GB/s
Read throughput^①	min{1.4 × Capacity, 2,000} MB/s	2 × min{1.4 × Capacity, 2,000} MB/s
Maximum write throughput	1.2 GB/s	2.4 GB/s
Write throughput^①	min{0.85 × Capacity, 1,200} MB/s	2 × min{0.85 × Capacity, 1,200} MB/s
Access latency	Several microseconds

^① In the following examples, a local NVMe SSD is used to describe how to calculate single-disk performance:

Single-disk write IOPS: Each GiB of capacity produces 165 write IOPS for up to 240,000 IOPS per disk.
Single-disk write throughput: Each GiB of capacity produces a write throughput of 0.85 MB/s for a maximum of 1,200 MB/s.

^② Overall instance performance data in the preceding table applies only to the ecs.i1.14xlarge instance type and represents the highest performance levels of local storage in the i1 instance family.

Local SATA HDDs

The following table describes the performance metrics of local SATA HDDs.

Metric	d1 and d1ne		d2c		d2s		d3s
Metric	Single-disk performance	Overall instance performance	Single-disk performance	Overall instance performance	Single-disk performance	Overall instance performance	Single-disk performance	Overall instance performance
Maximum capacity	5,500 GiB	154,000 GiB	3,700 GiB	44,400 GiB	7,300 GiB	219,000 GiB	11,100 GiB	355,200 GiB
Maximum throughput	190 MB/s	5,320 MB/s	190 MB/s	2,280 MB/s	190 MB/s	5,700 MB/s	260 MB/s	8,320 MB/s
Access latency	Several milliseconds

Note

The overall instance performance data in the preceding table applies only to the ecs.d1.14xlarge, ecs.d1ne.14xlarge, ecs.d2c.24xlarge, ecs.d2s.20xlarge, and ecs.d3s.16xlarge instance types and represents the highest performance levels of local storage in the corresponding instance families.

Data block size (KiB)	Maximum IOPS	Throughput
4	Approximately 25,000	Approximately 100
16	Approximately 17,200	Approximately 260
32	Approximately 9,600	Approximately 300
64	Approximately 4,800	Approximately 300