sequential read
It can be seen that in the case of continuous reading of 4KB packets:
The speed of SSD can reach 404M/S, and the IOPS can reach 103K/S
The speed of SAS can reach 190M/S, and the IOPS can reach 41K/S
SATA speed can reach 124M/S, IOPS can reach 31K/S
In sequential read, the overall performance of SAS is 1.5 times that of SATA hard disks, and the overall performance of SSD is 4 times that of SATA hard disks.
write sequentially
In the case of the same sequential write of 4KB packets,
The speed of SSD can reach 592M/S, and the IOPS can reach 152K/S
The speed of SAS can reach 190M/S, and the IOPS can reach 36K/S
SATA speed can reach 118M/S, IOPS can reach 31K/S
In sequential writing, the overall performance of SAS is the same order of magnitude as that of SATA hard disks, while the overall performance of SSD exceeds that of SATA and SAS.
random read
In the case of random read of the same 4KB data packet,
The speed of SSD can reach 505M/S, and the IOPS can reach 129K/S
The speed of SAS can reach 1784K/S, and the IOPS can reach 456/S
SATA speed can reach 466K/S, IOPS can reach 114/S
In random read, the overall performance of SAS is 4 times that of SATA hard disks, and the overall performance of SSD is more than a thousand times that of SATA hard disks.
random write
In the case of random writing of the same 4KB data packet,
The speed of SSD can reach 549M/S, and the IOPS can reach 140K/S
The speed of SAS can reach 1950K/S, and the IOPS can reach 512/S
The speed of SATA can reach 548K/S, and the IOPS can reach 134/S
In the next random write operation of 4KB data packets, the SSD card once again demonstrated its superb IO performance, with a random write rate of up to 549M/S and an IOPS of up to 140K. In comparison, the overall performance of SSDs is more than a thousand times that of SATA hard drives.
in conclusion:
1. The random read and write capabilities of SATA and SAS mechanical hard drives are weak, while the sequential read and write capabilities are basically at the same order of magnitude as SSDs, especially the sequential read and write performance of large files is better
2. The strength of SSD is random IO read and write, which is basically comparable to the access speed of memory. Of course, its sequential read and write capability is also at a relatively high level.
3. Random reading of small blocks of files is the scenario where solid-state storage has the greatest advantage over traditional disks. In contrast to disks, solid-state storage devices do not have seek times. As a result, its performance is 150x to 250x higher than that of the single best performing conventional disk
4. 受寻道时间这个机械因素影响，传统磁盘在随机读写场景，基本没有优势，由于磁盘读和写两个操作时间大概相同，所以随机读和随机写，单块磁盘的性能基本差不多
5. 对持续的大块写入请求，固态存储耗费擦除操作（耗时长）的时间大幅增加，而传统的磁盘却好相反，耗时长的寻道操作大幅减小，一次寻道，多次写入
6. 传统磁盘，受寻道机械操作影响，在随机操作场景性能不佳，而在大块，持续写入的场景由于寻道操作相对减少，其表现较好，比较适合性能要求不高，对容量较高的场景。