First things first, currently you have a Geforce 4 mx 420 installed. The line
0000:01:00.0 VGA compatible controller: nVidia Corporation NV17 [GeForce4 MX 420] (rev a3)
shows that. The 01:00.0 is the identifier for your agp slot (in rare circumstances you may need to know that for setting up X ).
Thanks for that kilgoretrout, erm presumably you derived that info from the
quote:0000:00:01.0 PCI bridge: Intel Corp. 82845 845 (Brookdale) Chipset AGP Bridge (rev 04)
line ? and that (rev 04) suggests a max of 4X agp ???
The (rev 04) suggests that the hardware is in its fourth revision with your motherboard. To be able to find out the speed of your AGP, you would need to look up the specifications for your motherboard's chipset (845 Brookdale) either in one of your manuals for your computer or on the web.
With compatibility for videocards, any newer non-PCI-express card should be right. 8X agp cards will work in any motherboard that has at least a AGP 2.0 compliant slot (4X agp) but will probably not work in 2x agp slots.
As with which video card you should buy, you should look at how much you are willing to pay, what you will be using it for, whether it is better then what you already have and how supported it is in linux. From the sounds of it, you are not after a whiz bang video card like the latest nvidia and ati cards so the speed of your processor does not really factor in.
See the HCL lists here for linux support and also search on the web (www.google.com/linux
) to see if any one is having troubles with the card that you plan on buying.
I would recommend that you do not get an ATI card at the moment (if you are after a card that will let you play 3d games like quake 3) because their linux support is wanting. NVIDIA provides good proprietry drivers that I have had no troubles with and requires minimal configuration.
With other brands of video cards (eg. Matrox, S3 etc ) I cannot comment because I have had no experience with them in linux (or windows for that matter).
HTH, if you need any more information or clarifications or have any other questions, don't hesitate to ask. The only silly question is the one not asked