I found that by default the nvidia drivers do not enable AGP FastWrites or Side Band Addressing. Here is a quick and easy way to turn it on.

NOTE To enable fastwrite you must have a motherboard that supports it, and have it turned on in the BIOS. Most AMD boards have fastwrite capability. I am not sure about Pentium based boards.

*(This tip requires a reboot. Unloading and reloading the driver just gets you an unstable system:/)*

First check to see if the FastWrites and SBA is enabled or disabled.

$ cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 4x
Fast Writes: Enabled
SBA: Enabled

THis may say disabled. My system has FW and SBA turned on.
Now before enabling fastwrites and sba make sure that your video card supports it. The Geforce 2 GTS cards and Geforce Ti cards support it. I am not sure if the MX cards do.

$ cat /proc/driver/nvidia/agp/card
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000217:0x1f000314

If your card supports FW and SBA then just do the following:
For Gentoo edit /etc/modules.d/nvidia
For Most other Distro's edit /etc/modules.conf

Add the following:
alias char-major-195 NVdriver
options NVdriver NVreg_EnableAGPSBA=1 NVreg_EnableAGPFW=1

NOTE: As of the 4191 drivers, the kernel module/driver is now called nvidia instead of NVdriver so please change the above to suit the drivers you are using.

Reboot. To make sure that the Fastwrite and SBA are enabled just

$ cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 4x
Fast Writes: Enabled
SBA: Enabled

Again and make sure that Fast Writes and SBA are enabled.

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by elboricua edited by howe81
last modified: 2003-01-29 20:25:54