SSD 性能与 HDD 性能对比

Question

我有两台服务器，一台带有 SSD，一台带有 HDD。我一直在运行 hdparm 来查看差异，但是 Timing cached reading 和 Timing 的结果相当相等/HDD 更快：

固态硬盘：

Timing cached reads:        26080 MB in  2.00 seconds = 13053.64 MB/sec
Timing buffered disk reads: 1558 MB in   3.00 seconds = 518.77 MB/sec

Timing O_DIRECT cached reads:   966 MB in  2.00 seconds = 482.99 MB/sec
Timing O_DIRECT disk reads:    1528 MB in  3.00 seconds = 508.71 MB/sec

硬盘：

 Timing cached reads:        28248 MB in  2.00 seconds = 14137.88 MB/sec
 Timing buffered disk reads: 496 MB in    3.01 seconds = 164.78 MB/sec

 Timing O_DIRECT cached reads:   994 MB in  2.00 seconds = 496.24 MB/sec
 Timing O_DIRECT disk reads:     486 MB in  3.01 seconds = 161.55 MB/sec

SSD 上的缓冲磁盘读取速度更快，但我不确定是否应该担心上述性能？如果有必要/可能，我该如何改进？

Answer 1

缓存的读取不是来自底层设备。它们根本不能代表不同设备的性能，这两种设备都无法接近这种吞吐量。忽略那个数字。