I have an HP with an AMD running at 2 GHz, 512 MB memory. It had an NVidia MX420. All was well until I hit Seattle. With all the sliders to maximum, which is the way I want it, Frame Rate fell to 10 or 12 per second.
So, I went out and bought an Nvidia FX5600, supposedly a surubambam as video cards go.
Installed all the latest drivers, etc., etc.. Went to Seattle, frame rate remains at 10 or 12!!!
Checked everything, memory doesn't seem to be a bottleneck, the video adapter, according to Windows XP My Computer Device Manager, is running fine.