Chromium is unresponsive and slow while scrolling and highlighting.
 

Chromium 31.0.1650.57 64-bit. Slackware 64 14.1.

Chromium very slow and unresponsive. Vertical scrollbar unresponsive and highlighting very slow.

Tried with and without direct rendering and hardware compositing. Have touchpad options disabled.

Is this because Xorg 2D is slow? I'm using nouveau with a PCX 5750 and mostly everything seems plenty fast (except chromium).

is this the gpu: http://vr-zone.com/articles/msi-pcx-...view/1529.html ?
from 2004? that's ancient.
my experience is that nouveau does not run well with legacy hardware.
you might get better performance with a legacy nvidia driver.
this archwiki article will help you to find the proper driver: https://wiki.archlinux.org/index.php/NVIDIA#Installing

Try another browser. If your specs are low, Chrome ain't the way to go. Check Firefox/Iceweasel performance.

^ iceweasel/firefox isn't going to be better in that respect.

holering should use the proprietary legacy nvidia driver for that card (if available).

if that's not an option, then you have to go really lightweight with your browser.
start with midori and work your way down lightweightness scale: dwb, (many more...) dillo.