AGP Mode 4

[Joeman1]

I was reading the README file that came from the web site when I downloaded my drivers and I noticed that I have the ability to change the default mode of the AGP card to mode 4. now, how exactly do I do this. I added this to the moduels.conf file:

alias char-major-195 NVdriver
options NVdriver NVreg_Enable4x=1

I have an i815 Chipset

But when I look at the messages log, it still stats MODE 2:

Oct 18 23:20:37 linuxbox kernel: agpgart: Detected Intel i815 chipsetOct 18 23:20:37 linuxbox kernel: agpgart: Detected Intel i815 chipset
Oct 18 23:20:37 linuxbox kernel: agpgart: AGP aperture is 64M @ 0xf8000000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: Intel i815 chipset
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: aperture: 64M @ 0xf8000000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: aperture mapped from 0xf8000000 to 0xd9ad2000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: mode 2x
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: allocated 16 pages

Oct 18 23:20:37 linuxbox kernel: agpgart: AGP aperture is 64M @ 0xf8000000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: Intel i815 chipset
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: aperture: 64M @ 0xf8000000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: aperture mapped from 0xf8000000 to 0xd9ad2000
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: mode 2x
Oct 18 23:20:43 linuxbox kernel: NVRM: AGPGART: allocated 16 pages

I am using Red Hat 8.0 and have a GeForce 4 MX 440. The drivers work great except for the slower speed.

Is this the proper way to do this, or is there another way.

Thanks for the assistance

Oh, BTW, I set the BIOS to mode x4

Joe

[Joeman1]

Well, I read through the docs and I mod'ed the os-registry file to enable fw and sb, and I set the NVreg_ReqAGPRate = 7 (thinking that would set the mode to 4) and I took a look at the /proc section and this is what I got

cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 2x
Fast Writes: Disabled
SBA: Disabled

To be more exact, the motherboard Im using is the ASUS TUSL2-C. Any assistance to this would be appreciated.

For some reason, none of the settings are working for me. Do I have to remove the existing drivers before I rebuild the drivers?

Thanks again

Joe

[Klaus-P]

These two links should be of some interest for you:

http://developer.intel.com/technology/agp/tutorial/index.htm

http://developer.intel.com/technology/3d/docs/index.htm

Correct setting AGP and related driver stuff is sometimes confusing and
indeed complex. Try to check out the Intel docs about chipsets, AGP, etc,...

[Klaus-P]

Cont...

Well what you have enabled namely "NVreg_ReqAGPrate = 7"

will not be recognized unless you ALSO remove the two leading
underscores, i.e. __ReqAGPRate (in line 330 of osregistry.c (3123 version)
But be aware that wrong or bad AGP rates could lead to a crash.

[bwkaz]

options NVdriver NVreg_Enable4x=1 I assume you mean NVreg_EnableVia4x, right? There is no such option NVreg_Enable4x. The reason is that by default, the driver picks the best AGP rate that both the card and motherboard can handle, and then when nVidia sees a lot of problems with certain e.g. chipsets (like Via's), they drop the AGP rate back down for those chipsets. Then they put options like this in the module to disable the rate-drop behavior, so if your specific chipset isn't buggy (like my KT333 isn't), you can enable those options to get the highest supported rate back.

Since you have an i815, none of this applies to you since there aren't really many problems with that chipset -- at least, that's what I gather since there aren't any options to turn it off, and on my i815 (my router/firewall), 4x mode is on as well (but that's a GF2 GTS, so maybe it's the card...)

Anyway, you can check what modes different pieces of the puzzle support by looking at /proc/driver/nvidia/agp/card and /proc/driver/nvidia/agp/host-bridge. For example, mine, on my i815, look like this (type in the stuff in bold, not the rest of it, to find out on your machine ;) ):

[root@3dguios root]# cat /proc/driver/nvidia/agp/card
Fast Writes: Supported
SBA: Not Supported
AGP Rates: 4x 2x 1x
Registers: <this doesn't matter>
[root@3dguios root]#
[root@3dguios root]# cat /proc/driver/nvidia/agp/host-bridge
Host Bridge: Intel 815
Fast Writes: Not Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: <again, doesn't matter>So if I were to try to enable both SBA and FW, for example, neither one would work (which is ... odd, since I had SBA working before... oh well, I don't use that machine for graphics anyway anymore, so it's not a huge deal), since the card doesn't support one, and the host bridge doesn't support the other. I would get AGP 4x though, because that's the highest rate that they both support.

Try checking into those files (host-bridge and card, that is), and see if you can figure out which one isn't letting you get higher AGP rates.

[Joeman1]

Interesting that the host-bridge and the card settings are opposite like that.. Mine is the same way:

cat /proc/driver/nvidia/agp/card
Fast Writes: Supported
SBA: Not Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000017:0x1f000102


cat /proc/driver/nvidia/agp/host-bridge
Host Bridge: Intel i815
Fast Writes: Not Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000207:0x00000102


So I guess the best I can hope for is AGP 4X, which Im having problems setting. It was noted on another post to make sure that the __ReqAGPRate was set to ReqAGPRate, but is that the correct setting for NVreg_ReqAGPrate? Is 7 the correct number to force the card to a MODE 4, or will I also have to add this line:

options NVdriver NVreg_ReqAGPRate=4

to my modules.conf file as well?

Sorry for all the newb questions here. Im sort of the curious type and I love to play games on Linux :-D

Thanks again...