Disk Specifications

Disks with different specifications provide difference performance. Major disk performance metrics include:

IOPS: the number of read/write operations performed by an EVS disk per second
Throughput: the amount of data read from and written to an EVS disk per second
Read/Write I/O latency: the minimum interval between two consecutive read/write operations on an EVS disk

You can choose whichever disk type is the best fit for your applications. If your existing disks no longer meet your performance requirements, you can change the disk type to upgrade the disk performance.

Extreme SSD

**Table 1** Extreme SSD performance data
Parameter	Extreme SSD
Max. capacity (GiB)	System disk: 1,024 Data disk: 32,768
Short description	Superfast disks for workloads demanding ultra-high bandwidth and ultra-low latency
Typical scenarios	Databases Oracle SQL Server ClickHouse AI scenarios
Max. IOPS^a	128,000
Max. throughput^a (MiB/s)	1,000
Burst IOPS limit^a	64,000
Disk IOPS^c	Min. [128,000, 1,800 + 50 x Capacity (GiB)]
Disk throughput^b (MiB/s)	Min. [1,000, 120 + 0.5 × Capacity (GiB)]
Single-queue access latency^d (ms)	Sub-milliseconds
API name^e	ESSD

General Purpose SSD V2

**Table 2** General Purpose SSD V2 performance data
Parameter	General Purpose SSD V2
Max. capacity	System disk: 1,024 GiB Data disk: 32,768 GiB
Short description	General-purpose SSD-backed disks targeting for transactional workloads with optimized performance and cost
Typical scenarios	Interactive workloads that demand high performance and low latency Enterprise OA and virtual desktops Large-scale development and test environments Transcoding services System disks Medium- and large-sized databases (SQL Server, Oracle, NoSQL, and PostgreSQL)
Max. IOPS^a	128,000
Max. throughput^a (MiB/s)	1,000 MiB/s
Burst IOPS limit^a	N/A
Disk IOPS^c	You preconfigure an IOPS ranging from 3,000 to 128,000. This IOPS must also be less than or equal to 500 times the capacity.
Disk throughput^b (MiB/s)	You preconfigure a throughput ranging from 125 to 1,000 MiB/s. This throughput must also be less than or equal to the IOPS divided by 4.
Single-queue access latency^d (ms)	1 ms
API name^e	GPSSD2

General Purpose SSD

**Table 3** General Purpose SSD performance data
Parameter	General Purpose SSD
Max. capacity (GiB)	System disk: 1,024 Data disk: 32,768
Short description	Cost-effective disks for enterprise systems with medium performance requirements
Typical scenarios	Enterprise OA Medium-scale development and test environments Small- and medium-sized databases Web applications System disks
Max. IOPS^a	20,000
Max. throughput^a (MiB/s)	250
Burst IOPS limit^a	8,000
Disk IOPS^c	Min. [20,000, 1,800 + 12 x Capacity (GiB)]
Disk throughput^b (MiB/s)	Min. [250, 100 + 0.5 × Capacity (GiB)]
Single-queue access latency^d (ms)	1
API name^e	GPSSD

Ultra-high I/O

**Table 4** Ultra-high I/O performance data
Parameter	Ultra-high I/O
Max. capacity (GiB)	System disk: 1,024 Data disk: 32,768
Short description	High performance disks excellent for enterprise mission-critical services as well as workloads demanding high throughput and low latency
Typical scenarios	Transcoding services I/O-intensive workloads NoSQL Oracle SQL Server PostgreSQL Latency-sensitive applications Redis Memcache
Max. IOPS^a	50,000
Max. throughput^a (MiB/s)	350
Burst IOPS limit^a	16,000
Disk IOPS^c	Min. [50,000, 1,800 + 50 x Capacity (GiB)]
Disk throughput^b (MiB/s)	Min. [350, 120 + 0.5 × Capacity (GiB)]
Single-queue access latency^d (ms)	1
API name^e	SSD

High I/O

**Table 5** High I/O performance data
Parameter	High I/O
Max. capacity (GiB)	System disk: 1,024 Data disk: 32,768
Short description	Disks suitable for commonly accessed workloads^f
Typical scenarios	Common development and test environments
Max. IOPS^a	5,000
Max. throughput^a (MiB/s)	150
Burst IOPS limit^a	5,000
Disk IOPS^c	Min. [5,000, 1,800 + 8 x Capacity (GiB)]
Disk throughput^b (MiB/s)	Min. [150, 100 + 0.15 × Capacity (GiB)]
Single-queue access latency^d (ms)	1–3
API name^e	SAS

Common I/O (Previous Generation Product)

**Table 6** Common I/O performance data
Parameter	Common I/O (Previous Generation Product)
Max. capacity (GiB)	System disk: 1,024 Data disk: 32,768
Short description	Disks suitable for less commonly accessed workloads
Typical scenarios	Applications demanding large capacity, medium read/write speed, but having fewer transactions Common office applications Lightweight development and test environments Not recommended to be used as system disks
Max. IOPS^a	2,200
Max. throughput^a (MiB/s)	50
Burst IOPS limit^a	2,200
Disk IOPS^c	Min. [2,200, 500 + 2 x Capacity (GiB)]
Disk throughput^b (MiB/s)	50
Single-queue access latency^d (ms)	5–10
API name^e	SATA

a: The maximum IOPS, maximum throughput, and burst IOPS limit all include both the read and write operations. So, maximum IOPS = read IOPS + write IOPS.

b: Take Ultra-high I/O for example: The baseline throughput is 120 MiB/s. The throughput increases by 0.5 MiB/s for every one GiB added until it reaches the maximum throughput 350 MiB/s.

c: Take Ultra-high I/O for example: The baseline IOPS is 1,800. The IOPS increases by 50 for every one GiB added until it reaches the maximum IOPS 50,000.

d: Single queue refers to performance when the queue depth or concurrency is 1. The single-queue access latency is the I/O latency when all I/O requests are processed sequentially. The values in the table are calculated with 4 KiB data blocks.

e: This API name is the value of the volume_type parameter in the EVS API. It does not represent the type of the underlying hardware device.

f: High I/O disks (except for those created in dedicated storage pools) are HDD-backed disks. They are suitable for applications with commonly accessed workloads. The baseline throughput of a high I/O disk is 40 MiB/s per TiB, and the maximum throughput of a high I/O disk is 150 MiB/s. If your applications have high workloads, it is recommended that you choose SSD-backed disks which have higher specifications.

Next topic: Restrictions on Buying Cold HDD EVS Disks