Comment 73 for bug 88815

Timo,

By coincidence Michel Danzer and I were experimenting with packages he built sans xcb, see the upstream bug: https://bugs.freedesktop.org/show_bug.cgi?id=10173

What we discovered is that it's definitely caused by xcb, and it's a client-side issue - respawning metacity after changing the packages will trigger the slowness/speedup, without an X server restart.