hardware - What's the lightest Ubuntu desktop environment?

My computer has 1GB ram and a very end low graphics card, but I don't know how much power it has.

Unity is very slow on my computer, and I saw that there are many desktop environments which are much lighter and faster, even for a slow computer.

So, what's the lightest desktop environment?

Definitely Lxde
or Xfce.

First remove Unity with this command (make a backup before proceeding for safety!):

sudo apt-get autoremove --purge unity unity-common unity-services unity-lens-\* unity-scope-\* unity-webapps-\* gnome-control-center-unity hud libunity-core-6\* libunity-misc4 libunity-webapps\* appmenu-gtk appmenu-gtk3 appmenu-qt\* overlay-scrollbar\* activity-log-manager-control-center firefox-globalmenu thunderbird-globalmenu libufe-xidgetter0 xul-ext-unity xul-ext-webaccounts webaccounts-extension-common xul-ext-websites-integration gnome-control-center gnome-session

then:

sudo rm /usr/lib/thunderbird-addons/extensions/messagingmenu@mozilla.com.xpi

Now, to install Lxde run this command:

sudo apt-get install lubuntu-desktop

or for Xfce this one:

sudo apt-get install xubuntu-desktop

Lastly, reboot and enjoy!

Hope this helped you.