Thought I would put together a post of how I enabled the use of Nvidia's AGP driver (Option "NvAGP" "1" in xorg.conf) in Edgy. This assumes you have the Nvidia drivers installed.

If your like me '$ cat /proc/driver/nvidia/agp/status' will return:

Status: Enabled
Driver: AGPGART
AGP Rate: 8x
Fast Writes: Disabled
SBA: Disabled

You can change that by:

1. Stop AGPGART from being loaded by adding these lines to '/etc/modprobe.d/blacklist':
__________________________________________________ _____________________________________
# Stop hotplug from loading the via (or intel) graphics at startup so we can use the Nvidia.
# (Some people may have to disable this first).
#amd64_agp
blacklist agpgart
#blacklist intel_agp
blacklist via-agp
#amd64_agp
__________________________________________________ _____________________________________

2. Edit your '/etc/X11/xorg.conf' to include the line (without quotes) "Option "NVAGP" "1"" in the device section. Here is an example of mine:
__________________________________________________ _____________________________________
Section "Device"
Identifier "NVIDIA Corporation NV18 [GeForce4 MX 440 AGP 8x]"
Driver "nvidia"
BusID "PCI:1:0:0"
Option "NoLogo"
Option "RenderAccel" "true"
Option "NVAGP" "1"
## TV out setup.
Option "TVStandard" "PAL-I"
Option "TVOutFormat" "SVIDEO"
## Enables RGB workstation overlay visuals. This is only supported on Quadro4 and Quadro FX $
# Option "Overlay" "true"
Option "XvmcUsesTextures" "true"
## I set the overscan as 0.0 then use nvidia-settings.
Option "TVOverScan" "0.0"
EndSection
__________________________________________________ _____________________________________

3. Reboot!

Now running '$ cat /proc/driver/nvidia/agp/status' should return:

Status: Enabled
Driver: NVIDIA
AGP Rate: 4x
Fast Writes: Disabled
SBA: Disabled

Now make sure your boards support the last two options:

'$ cat /proc/driver/nvidia/agp/card'

'$ cat /proc/driver/nvidia/agp/host-bridge'

4. Providing you get 'supported' for Fast Writes and SBA you can enable them by adding this line to '/etc/modprobe.d/nvidia-kernel-nkc' after 'alias char-major-195* nvidia':

"options nvidia NVreg_EnableAGPSBA=1 NVreg_EnableAGPFW=1"

Reboot and 'cat /proc/driver/nvidia/agp/status' should return:

Status: Enabled
Driver: NVIDIA
AGP Rate: 4x
Fast Writes: Enabled
SBA: Enabled

I will say this gave me NO 'glxgears -printfps' speed increase but I think it does for some. I learned how to do this from lots of sources so if anyone knows more, post up!

Also, since doing this I can no longer run the 'nvidia-settings' gui without first commenting out the "options nvidia NVreg_EnableAGPSBA=1 NVreg_EnableAGPFW=1" line.

Hope this helps people.

Simon