Very slow boot time and poor perfomance

You have Sophos Anti-Virus for Linux installed:

sav-protect.service belongs to Sophos. Please read here. So does sav-rms.service.

sav-protect.service is Sophos Real-Time (On-Access) Scanning service.

sav-rms.service is Sophos Remote Management System service.

The delay is due to boot-time virus scan.While the sluggish overall performance is due to real-time (on-access) Scanning. Please read similar issues here, here and here.

It is worth noting that this is NOT an issue specific to Sophos. This is generally how Anti-Virus software work. They demand system resources to do their job and it gets worse with higher workloads. The more you use your system --> the more system and file access processes are triggered --> the more system resources are used up by both your regular processes and the Anti-Virus that scans them --> the more your system becomes sluggish and non-responding until it reaches a bottleneck and sometimes it halts.

If virus scan at boot-time and on-access is not critical for your system, you can disable the service and gain back speed at boot-time and system responsiveness. To do this, please run the following command in the terminal and reboot your system:

sudo systemctl disable sav-protect.service

If it shows up again after reboot, you can follow the above command with this:

sudo systemctl mask sav-protect.service

If you get alerts at boot-time about real-time protection being disabled, you can follow the above commands with this:

sudo systemctl disable sav-rms.service

If it shows up again after reboot, you can follow the above command with this:

sudo systemctl mask sav-rms.service

To roll back the above changes anytime, please run:

sudo systemctl unmask sav-protect.service

Then follow it with this:

sudo systemctl enable sav-protect.service

Then follow it with this:

sudo systemctl unmask sav-rms.service

Then follow it with this:

sudo systemctl enable sav-rms.service

Notice:

All the above is done without the need to uninstall Sophos Anti-Virus for Linux. It will remain on your system so that you can use other features of the Anti-Virus or you can later roll back the changes done above and go back to the full blown package as you wish.

Around 1 year ago on Debian 9 I had a 50% performance decrease on gcc compilation. Page Table Isolation caused this, it has something todo with Spectra/Meltdown. You could add -no-pti from grub on startup. Note that this was on a Haswell i7 and only when using 32 bits Linux, on 64 bits there are is no such big performance decrease.

Are you using 32 or 64 bits?