ubuntu - ssd performance against hdd performance

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I have two server, one with
a SSD, one with a HDD. I've been running hdparm to see the differences, but the results
for Timing cached reads and Timing are quite equal/HDD is
faster:

SSD:

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

HDD:

            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

The
buffered disk reads are way faster on the SSD, but I'm unsure if I should worry about
above mentioned performance? How could I improve this if
necessary/possible?

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class="normal">Answer

The
cached reads aren't from the underlying device. They aren't representative at all of the
performance of the different devices, neither of which could come anywhere near that
kind of throughput. Ignore that number.