Those of you running old ATI cards or integrated laptop video chipsets rejoice. I believe I have found the best replacement for all ATI cards having the slowdown issue. It is the fastest replacement yet.
Find the oldest FireGL driver for your version of windows. It should be called FireGL 4/3/2/1. Download the “Performance driver for 3ds Max/Autodesk VIZ”
Select the second option and extract to c:\ATI\support
It will continue from there and tell you that it has not found the FireGL chipset. Close it and go to c:\ATI\support.
You will find a file called FGLMAX.dll. Rename this file to atioglxx.dll and stick it in your Blender directory.
This fix may or maynot work with your card. It worked for my laptop’s video chipset, which is a Radeon Xpress 1100 (200M), BETTER than the one I found in the Blender wiki.
I previously used the FireGL dlls from http://en.wikibooks.org/wiki/Blender_3D:_Troubleshooting and it worked. But when I wanted to sculpt it would get really slow at higher levels (even 100,000 polys), so I began searching for a replacement. I’ve tried new and old, both Radeon and FireGL, I believe this to be the fastest.