Try this

A few years ago, it was possible to tweak the ATA disks with the
hdparm command, in particular with the -u option, that unmasks the
interrupts during a disk access.

However, the ATA kernel driver has been replaced by a specific SCSI layer
for ATA disks; hdparm -u doesn’t work anymore.

Nevertheless it is possible to restore the functionality with the
little bash script below. Apply it as root, and run a huge disk-to-disk or
disk-to-network copy and while copying, do something on your desktop:
open a directory on Dolphin, run firefox, etc… you should get a far
shorter reaction time from the desktop than without the script.

You won’t get a better throughput from the disks, but the general
reaction time of your system will be improved. Be careful with this
script: some old disks may not support it and unleash havoc on your
system.


#!/bin/bash

for i in /sys/bus/scsi/devices/target*; do
         $i =~ /sys/bus/scsi/devices/target(.*) ]]
        T=${BASH_REMATCH[1]}
        T="$i/$T:0"
        echo enabled > $i/power/async
        echo enabled > $T/power/async
        for j in $T/block/*; do
                if  -w $j/power/async ]; then
                        echo enabled > $j/power/async
                fi
        done
        for j in $T/scsi_disk/*; do
                if  -w $j/power/async ]; then
                        echo enabled > $j/power/async
                fi
        done
done