Recently I decided to check out openSUSE's version of the Mate desktop. Pretty cool, but one thing I noticed was that Xorg seems to use a lot more memory in Mate than KDE. Emphasis on "seems," because the comparison may not be valid.

While I was in Mate I used mate-task-manager to view resource usage, and in KDE I used ksysguard. I uninstalled Mate before I thought to check both with the same tool.

Right now, in KDE, Xorg memory usage shows:
Memory Shared Memory
14,228 K 45,036 K

In Mate, the memory usage of Xorg started around 25 M but soon would go up to around 50 M. Maybe that 50 M was shared memory, which would be comparable to KDE.

Anyone know a little more about how to interpret these numbers you get from the various resource monitors?

If Xorg does use more memory in some DE's than others, why?