Both comments are true. In some Linux distros the problem is the
resource-hungry GUI but it is easy to install a lighter and faster desktop
environment if Gnome is not convenient. Sometimes I find it convenient sometimes
not, depending in what mood I am (or maybe air pressure before the rain ?) and
when I do not want to use Gnome i log into another session, using FVWM or XFCE,
for example, which are lightweight and fast, like pretty little butterflies.
I bet a desktop environment like LXDE is faster than Windows XP ! But I do
not use LXDE.
And I bet that XFCE under Dreamlinux for example is even faster, something
like the speed of Windows 2000. Incredible, but true.
Yes, Windows 2000 and XP when clean and new are faster than the heavier
graphical interfaces of the major Linux distros.
One of Microsoft's merits, until recently when they expertly messed up the
whole thing with Vista was that their products could be run on the weakest
computers on the market. XP, for example, can be installed and used on a PC with
128 or even 92 MB of RAM and 2 GB hard disk (as I experienced) but Ubuntu
cannot. It is hard to find a Linux distro that runs on such hardware.
Windows 2000 flew on a PC with 200 MHz processor and 64 MB of RAM but the
only Linux distros I could run on it were Damn Small Linux (this one was really
very usable installed on the hard disk !) and Fat Free, a Puppy derivative.
So, Ubuntu is not for old and very weak computers.
By the way, this Gnome desktop in ubuntu is very comfortable and usable on my
PC with 2.66 GHz processor and 1 GB of RAM but KDE4 is....I have no words.
Quite much time ago i tried OpenSUSE. Its KDE4 I considered barely usable,
like trying to push a wagon, but I installed XFCE and that was really fast and
usable.