The clue is here:
NCQ disabled due to excessive errors.
I found the solution here:
"6. If you get some System Freeze
In case your system is showing some type of freeze, it may come from the fact that your SSD disk is not compatible with Linux NCQ (SATA Native Command Queueing), which is enabled by default.
This should not be the case with modern SSD, but it happens with some old generation or no-name ones.
To disable NCQ,you need to add the kernel parameter libata.force=noncq.
# sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash libata.force=noncq"
Once modified, propagate it to grub database :
# sudo update-grub
After next reboot, these freezes should be part of the past.
Your computer should now be more responsive and your SSD life expectancy should have increased quite a bit.
Hope it helps".
Strange nobody in this forum was aware of the problem?
But now my Ubuntu boots as fast as my Win8 on the same computer. Nice!