Hard disk enclosure performance indicators generally include IOPS (Input Output Operations Per Second, reflecting random read and write performance), plastic 2.5 usb 3.0 hdd enclosure throughput (Throughput, in MB/s, reflecting sequential read and write performance), Response Time /Latency (response time/delay, in ms or μs).
IOPS: Unit IOPS, that is, the number of IO requests completed by the device per second, plastic 2.5 usb 3.0 hdd enclosure is generally the number of responses to small block data read and write commands, such as 4KB data block size. The higher the IOPS number, the better.
Throughput: unit MB/s, that is, the amount of data transmission completed by read and write commands per second, also called bandwidth (Bandwidth). Generally, it is a large block of data read and write commands, such as 512KB data block size. The higher the throughput, the better.
Response time: also called Latency, plastic 2.5 usb 3.0 hdd enclosure is the response time required for each command from sending to receiving status reply. The latency indicators include Average Latency and Maximum Latency Two (Max Latency). The lower the response time, the better.
2. access mode
The Access Pattern should be considered in the design of the performance test of plastic 2.5 usb 3.0 hdd enclosure, including the following three parts:
Random/Sequential: Random and sequential data command requests. What is random and continuous for plastic 2.5 usb 3.0 hdd enclosure? It refers to whether the LBA addresses of the two commands before and after are consecutive. The consecutive addresses are called Sequential, and the discontinuous addresses are called Random.
·Block Size: block size, plastic 2.5 usb 3.0 hdd enclosure is the data size transmitted by a single command, and the performance test ranges from 4KB to 512KB. The random test of plastic 2.5 usb 3.0 hdd enclosure generally uses small data blocks, such as 4KB; the sequential test generally uses large data blocks, such as 512KB.
·Read/Write Ratio: The ratio of the number of read and write commands mixed.
plastic 2.5 usb 3.0 hdd enclosure any test workload is a combination of these modes, for example:
1) Sequential read test: refers to LBA continuous reading, the block size is 256KB, 512KB and other large-sized data blocks, and the read-write ratio is 100%: 0;
2) Random write test: refers to the discontinuous writing of LBA, the block size is generally 4KB, and the read-write ratio is 0:100%;
3) Random mixed read and write: refers to the LBA discontinuous read and write mixed test, the block size is generally 4KB, and the read and write maintains a certain ratio.
3. Latency indicator
The plastic 2.5 usb 3.0 hdd enclosure has an average delay and a maximum delay. The lower the value, the better. The average delay calculation formula of plastic 2.5 usb 3.0 hdd enclosure is the sum of all command response times in the entire application or test process divided by the number of commands, which reflects the overall average delay performance of the SSD; the maximum delay is within the test period. The one with the longest response time among all commands reflects the user experience. For example, the maximum delay affects the user experience of whether the application is stuck when operating the SSD through the operating system. The delay of the plastic 2.5 usb 3.0 hdd enclosure is on the order of seconds, and the user will experience obvious lag.
4. Service Quality Indicators
The quality of service (QoS) of the plastic 2.5 usb 3.0 hdd enclosure expresses the "confidence level" of the delay. As shown in Figure 1-20, two 9s (99% ) to 5 9 (99.999%) percentage of the command with the largest delay (Max Latency), plastic 2.5 usb 3.0 hdd enclosure is the response time of the slowest command. On the whole, the QoS delay distribution of an SSD disk is as far to the left as possible, and the smaller the instant delay, the better.
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