Block storage performance and pricing differ across types. Select the appropriate block storage products based on your specific workloads and application needs. This topic covers the performance metrics and specifications for cloud disks and local disks, along with elastic ephemeral disks.
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For details on block storage pricing and billing, see Block storage billing.
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For an overview of block storage features and use scenarios, see Block storage overview.
Performance metrics
Key metrics for block storage performance include IOPS, throughput, and latency. Performance for certain block storage products correlates with capacity. For instance, ESSDs with varying performance levels have specific capacity requirements.
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I/O size
I/O size refers to the data size in each read/write operation, such as 4 KiB. It impacts the performance metrics IOPS and throughput: IOPS × I/O size = throughput. Hence, different I/O sizes necessitate a focus on corresponding performance metrics.
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IOPS (input/output operations per second): Reflects the number of I/O operations a block storage can handle per second, indicating its read/write capacity. Unit: operations/second.
For latency-sensitive random small I/O operations, such as those in database applications, IOPS performance is crucial.
NoteIn database applications, frequent data insertions, updates, or deletions occur. High IOPS ensures efficient system operation under numerous random read/write operations, preventing performance drops or increased latency due to I/O bottlenecks.
Throughput: Measures data transfer per second. Unit: MB/s.
Applications with sequential read/write operations or large I/Os, like database applications, should prioritize throughput.
NoteOffline computing tasks, such as those performed by Hadoop, involve petabyte-scale data analysis and processing. Insufficient throughput can extend overall processing times, impacting business efficiency and response times.
Latency: The time taken for a block storage device to process an I/O request. Units: seconds, milliseconds, or microseconds. High latency can degrade performance or cause errors in latency-sensitive applications.
For applications sensitive to high latency, such as databases, consider using low-latency disks like ESSD AutoPL disks or ESSDs.
Capacity: The storage space available. Units: TiB, GiB, MiB, KiB.
Block storage capacity is expressed in binary units, with 1 GiB equaling 1,024 MiB. Capacity isn't a performance metric but affects performance levels. Larger capacity block storage devices offer greater processing capabilities. Devices within the same category deliver consistent I/O performance per unit capacity, with cloud disk performance linearly increasing with capacity up to the category's single-disk maximum.
Disk performance
The table below describes the performance and typical applications for various cloud disk categories.
Cloud disk performance is not only bound by the disk's specifications but also by the attached instance's specifications. For more information, see storage I/O performance.
Standard SSDs, ultra disks, and basic disks represent previous generation cloud disks and may not be available in certain regions and zones. Consider using PL0 ESSDs or ESSD Entry disks as alternatives to ultra and basic disks, and ESSD AutoPL disks in place of standard SSDs.
Performance category | ESSD series disks | Previous generation disks | ||||||||
Zone-redundant ESSD (public preview) | ESSD AutoPL | PL3 ESSD | PL2 ESSD | PL1 ESSD | PL0 ESSD | ESSD Entry | Standard SSD | Ultra disk | Basic disk | |
Capacity range per disk (GiB) | 10~65,536 | 1~65,536 | 1,261~65,536 | 461~65,536 | 20~65,536 | 1~65,536 | 10~32,768 | 20~32,768 | 20~32,768 | 5~2,000 |
Maximum IOPS | 50,000 | 1,000,000 | 1,000,000 | 100,000 | 50,000 | 10,000 | 6,000 | 25,000② | 5,000 | Hundreds |
Maximum throughput (MB/s) | 350 | 4,096 | 4,000 | 750 | 350 | 180 | 150 | 300② | 140 | 30~40 |
Single-disk IOPS performance formula① | min{1,800 + 50 × Capacity, 50,000} | Baseline performance: max{min{1,800 + 50 × Capacity, 50,000}, 3,000} Provisioned performance: Capacity (GiB) <= 3: not configurable Capacity (GiB) >= 4: [1, min{(1,000 IOPS per GiB × Capacity - Baseline IOPS), 50,000}] Performance burst③: Actual final IOPS - Baseline IOPS - Provisioned IOPS | 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} | min{1,800 + 8 × Capacity, 6,000} | min{1,800 + 30 × Capacity, 25,000} | min{1,800 + 8 × Capacity, 5,000} | None |
Single-disk throughput performance formula (MB/s) ① | min{120 + 0.5 × Capacity, 350} | Baseline performance: max{min{120 + 0.5 × Capacity, 350}, 125} Provisioned performance: 16 KB × Provisioned IOPS / 1,024 Performance burst③: Actual final throughput - Baseline throughput - Provisioned throughput | 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 reliability | 99.9999999% | |||||||||
Average single-channel random write latency in milliseconds (block size = 4 KB) |
| 0.2 | 0.2 | 0.2 | 0.2 | 0.3~0.5 | 1~3 | 0.5~2 | 1~3 | 5~10 |
①Below are examples using an SSD Shared Block Storage device to calculate single disk performance:
Maximum IOPS for a PL0 ESSD: Baseline IOPS is 1,800, increasing by 12 IOPS for each additional GiB of storage, up to 10,000 IOPS.
Maximum throughput for a PL0 ESSD: Baseline throughput is 100 MB/s, increasing by 0.25 MB/s for each additional GiB of storage, up to 180 MB/s.
②Standard SSD performance varies with block size. Smaller blocks yield lower throughput but higher IOPS, as the following table shows.
I/O size (KiB)
Maximum IOPS
Throughput (MB/s)
4
Approximately 25,000
Approximately 100
16
Approximately 17,200
Approximately 260
32
Approximately 9,600
Approximately 300
64
Approximately 4,800
Approximately 300
③Beyond baseline and provisioned performance, ESSD AutoPL disks also offer burst capabilities. Monitor burst details in real-time with CloudLens for EBS, including burst duration and total burst I/O. For more details, see disk analysis.
Performance of local disks
Local disks are not standalone; their data reliability hinges on the physical server's reliability, posing a single point of failure risk. A failure in the physical server can impact multiple instances and risk data loss. Avoid using local disks for long-term data storage. For more on local disks, see local disks.
NVMe SSD local disks
Performance metrics for local NVMe SSDs used by the d3c compute-intensive big data instance family are described in the following table.
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
Performance metrics for local NVMe SSDs used by the i4 instance family are detailed in the table below.
NVMe SSD 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
NoteFor optimal performance, use the latest Linux images, such as Alibaba Cloud Linux 3, supported only by this instance family.
Performance metrics for local NVMe SSDs used by the i4g and i4r instance families are presented in the following table.
NVMe SSD 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
NoteThe 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.
Performance metrics for local NVMe SSDs used by the i3 instance family are shown in the table below.
NVMe SSD 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
NoteThe 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.
Performance metrics for local NVMe SSDs used by the i3g instance family are outlined in the following table.
NVMe SSD 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
NoteThe 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.
Performance metrics for local NVMe SSDs used by the i2 and i2g instance families are described in the table below.
NVMe SSD metric
Single-disk performance
Overall instance performance①
Only ecs.i2.xlarge and ecs.i2g.2xlarge
Other i2 and i2g specifications
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
Latency
Within microseconds (μs)
① Overall instance performance data is specific to the ecs.i2.16xlarge instance type, representing the peak local storage performance for the i2 family.
Performance metrics for local NVMe SSDs used by the i2ne and i2gne instance families are detailed in the following table.
NVMe SSD 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
Latency
Within microseconds (μs)
Performance metrics for local NVMe SSDs used by the i1 instance family are shown in the table below.
NVMe SSD 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
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
Latency
Within microseconds (μs)
① Below are examples using an NVMe SSD local disk to calculate single disk performance:
The write IOPS formula indicates each GiB of capacity contributes 165 write IOPS, up to 240,000 IOPS per disk.
The write throughput formula shows each GiB of capacity contributes 0.85 MB/s, up to a maximum of 1,200 MB/s.
② Overall instance performance data pertains only to the ecs.i1.14xlarge instance type, indicating the highest local storage performance for the i1 family.
SATA HDD local disks
Performance metrics for local SATA HDDs are provided in the table below.
SATA HDD metric | d1 and d1ne | d2c | d2s | d3s | ||||
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 |
Latency | Within milliseconds (ms) | |||||||
Overall instance performance data applies to specific instance types within the ecs.d1.14xlarge, ecs.d1ne.14xlarge, ecs.d2c.24xlarge, ecs.d2s.20xlarge, and ecs.d3s.16xlarge families, showcasing the top local storage performance for these families.
Elastic ephemeral disk performance
Customize the capacity of elastic ephemeral disks for temporary data storage. For more about elastic ephemeral disks, see elastic ephemeral disk.
Two categories of elastic ephemeral disks are available: standard and premium. Standard elastic ephemeral disks are suitable for scenarios with large data volumes and high throughput needs, while premium elastic ephemeral disks are suitable for scenarios requiring small capacity but high IOPS. The following table describes the performance of each type:
Metric | Standard elastic ephemeral disks | Premium elasitc ephemeral disks |
Single-disk capacity range (GiB) | 64 to 8,192 | 64 to 8,192 |
Maximum read IOPS per disk | Either 100 times the capacity or 820,000, whichever is smaller | Either 300 times the capacity or 1,000,000, whichever is smaller |
Maximum write IOPS per disk | Either 20 times the capacity or 160,000, whichever is smaller | Either 150 times the capacity or 500,000, whichever is smaller |
Maximum read throughput per disk (MB/s) | Either 0.8 times the capacity or 4,096, whichever is smaller | Either 1.6 times the capacity or 4,096, whichever is smaller |
Maximum write throughput per disk (MB/s) | Either 0.4 times the capacity or 2,048, whichever is smaller | Either the capacity or 2,048, whichever is smaller |
Write I/O density① | 20 | 150 |
Read I/O density① | 100 | 300 |
①: I/O density = IOPS / disk capacity, unit: IOPS/GiB, indicating the IOPS capability per GiB.
Test block storage performance
Assess block storage performance using the following methods:
Troubleshooting slow read/write or high I/O on cloud disks
Monitor cloud disk performance in the ECS console, EBS console, or CloudMonitor console to verify if it meets your business needs or to identify performance bottlenecks. For more information, see view cloud disk monitoring information.
Check if the cloud disk billing method is pay-as-you-go. If so, disk I/O may be throttled during overdue payment status but will resume once the account is recharged.
Note: If the account remains unpaid for 15 days after becoming overdue, the cloud disk will be released, and data cannot be recovered. Please be aware of this risk.
For Linux systems, consult how to check the I/O load on Linux systems to identify high IOPS consuming programs.
Data import performance is influenced by both client and server capabilities.
On the server side, use the atop tool to monitor Linux system metrics, which continuously tracks resource usage, recorded by default in the /var/log/atop directory for later analysis.
If cloud disk performance falls short of your business requirements, consider methods to enhance it as outlined in how to improve cloud disk performance.
How to improve cloud disk performance
To boost cloud disk performance, employ one of the following strategies:
Cloud disk performance is constrained by both the disk and instance specifications. If the instance's IOPS and bandwidth are lower than the disk's maximum, upgrading the instance is necessary to enhance performance. For details on instance limitations, see instance family.
Scenarios | Methods to improve performance |
When the cloud disk type (such as standard SSD) cannot meet the higher IOPS or throughput requirements brought by business growth, you can choose to change to a higher-performance cloud disk type, such as ESSD PL1, to obtain higher IOPS and better response time. This method is suitable for applications with strict storage performance requirements and significant growth in business scale or access volume. | |
If you are using an ESSD, you can adjust the performance level of the ESSD based on changes in business workload. | |
If you are using an ESSD AutoPL disk, you can set the pre-configured performance or enable performance burst to improve the disk performance. | |
When your business requires not only higher IOPS but also more storage space, it is recommended to scale out the cloud disk. For some types of cloud disks (such as ESSD PL1), the baseline IOPS will increase with the increase in capacity, thereby enhancing the processing capability and improving the performance of the cloud disk. This method is suitable for scenarios in which data volume continues to grow and requires larger storage capacity and higher IOPS. For example, the IOPS of a 40-GiB ESSD PL1 is 3,800, which increases to 6,800 when extended to 100 GiB. | |
To flexibly manage and optimize storage resource allocation and improve cloud disk performance, you can choose Logical Volume Manager (LVM). By distributing data across multiple logical volumes, you can achieve parallel processing of read and write operations, thereby improving cloud disk performance. This method is particularly suitable for multi-threaded applications and databases that require high concurrency access. | |
When you need to improve IOPS and throughput while ensuring data redundancy, you can choose to create a RAID array. For example, using RAID 0 can improve read and write speeds, while RAID 1 or RAID 10 can improve performance and provide data redundancy. |