hdparm
CautionDisk info and speed test
hdparm -I <dev>
Shows drive details (-I) and benchmarks raw reads (-tT) — turn 'feels slow' into numbers.
Examples
hdparm -tT /dev/sdaCached vs raw read speed
Syntax
hdparm -I <dev> / hdparm -tT <dev>
Before you run it
Some tuning flags are dangerous.
The same reference, with no signal at all
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