Ubuntu 16.04 LTS carrega visivelmente mais lento comparar com 14.04

Question

Depois de atualizar o Ubuntu para o 16.04 LTS, notei que o Ubuntu carrega visivelmente mais lento do que o 14.04. Isso significa que leva mais tempo para carregar a tela de login após a ativação do PC e muito mais intervalo entre a inserção de senha e o preenchimento da área de trabalho do Ubuntu. Existe uma maneira de corrigir esse problema?

EDIT: adicionado systemd-analyze blame output.

         14.737s networking.service
         13.727s apport.service
         13.666s speech-dispatcher.service
         11.593s dev-sda3.device
          9.058s iio-sensor-proxy.service
          9.055s rsyslog.service
          9.029s systemd-user-sessions.service
          8.979s thermald.service
          8.059s NetworkManager-wait-online.service
          7.600s apparmor.service
          7.314s accounts-daemon.service
          4.996s grub-common.service
          4.665s irqbalance.service
          4.638s ondemand.service
          4.155s console-setup.service
          3.771s lightdm.service
          3.414s systemd-tmpfiles-setup.service
          2.914s NetworkManager.service
          2.017s systemd-backlight@backlight:intel_backlight.service
          1.760s systemd-udevd.service
          1.479s resolvconf.service
          1.451s systemd-tmpfiles-setup-dev.service
          1.442s ModemManager.service
lines 1-23...skipping...
         14.737s networking.service
         13.727s apport.service
         13.666s speech-dispatcher.service
         11.593s dev-sda3.device
          9.058s iio-sensor-proxy.service
          9.055s rsyslog.service
          9.029s systemd-user-sessions.service
          8.979s thermald.service
          8.059s NetworkManager-wait-online.service
          7.600s apparmor.service
          7.314s accounts-daemon.service
          4.996s grub-common.service
          4.665s irqbalance.service
          4.638s ondemand.service
          4.155s console-setup.service
          3.771s lightdm.service
          3.414s systemd-tmpfiles-setup.service
          2.914s NetworkManager.service
          2.017s systemd-backlight@backlight:intel_backlight.service
          1.760s systemd-udevd.service
          1.479s resolvconf.service
          1.451s systemd-tmpfiles-setup-dev.service
          1.442s ModemManager.service
          1.208s plymouth-start.service
          1.035s systemd-journald.service
          1.000s systemd-modules-load.service
           918ms keyboard-setup.service
           905ms gpu-manager.service
           696ms upower.service
           688ms udisks2.service
           678ms systemd-update-utmp.service
           583ms dev-disk-by\x2duuid-b6b1a8eb\x2d15a0\x2d4f95\x2da7d4\x2df5291de0b7a8.swap
           541ms avahi-daemon.service
           502ms dev-mqueue.mount
           422ms ufw.service
           377ms polkitd.service
           332ms colord.service
           326ms kmod-static-nodes.service