I am currently working on my first bit of GNU and Ubuntu evangelism-- installing Hardy Heron on a friend's old Compaq Presario 700, with a Duron Mobile (1 GHz), 256MB SDRAM, and unfortunately, an S3 display adapter.

lspci reveals (specifically): S3 Inc. VT8636A [ProSavage KN133] AGP4X VGA Controller (TwisterK) (rev 01)

At least on this laptop Xorg 7.3 does not automatically use the appropriate driver (savage). Running displayconfig-gtk and checking the "Graphics Card" tab shows that no driver is selected in the "Driver" drop box. Attempting to use displayconfig-gtk to select the driver causes the tool to crash. Once I specify the driver in xorg.conf and restart X however, the driver loads. Running displayconfig-gtk now shows "savage" as the driver currently in use on the "Graphics Card" tab, and this poor laptop's CPU can finally focus on doing things other than drawing the screen.

I figured I'd post this for anyone having slow performance or graphics issues in Hardy.