Nvidia Driver AGP FastWrite and Side Band Addressing

elboricua

I got this tip from gleaning info from a few threads here on the gentoo boards, some from the infogrames boards, and some from reading through the nvidia documentation. I discovered this while trying to squeeze a few more FPS from my UT2003 install.

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

mooteel · n00b Joined: 18 Apr 2002 Posts: 8 Location: Montreal, QC

Just for the record, I have a ASUS, VIA based motherboard with a Pentium III and I have to enable Fast Writes in my BIOS too.

floam · Posted: Sat Nov 02, 2002 4:14 am Post subject:

be warned: enabling fastwrites can cause lots of system instability with some via chipsets.

roTor · n00b Joined: 21 Apr 2002 Posts: 55 Location: Atlanta, GA

ejwahl · Posted: Mon Nov 04, 2002 2:27 am Post subject:

No problems so far with an ABIT KG-7 (AMD 761 chipset), GeForce4 Ti 4400 and Flux...

Thanks for the tip...
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squanto · Posted: Mon Nov 04, 2002 6:14 am Post subject:

squanto · Posted: Mon Nov 04, 2002 8:43 am Post subject:

Well I guess on GF3Ti200 you cant turn on Fast Write and sba, but I wound up in the process of doing all this, to wind up building a new kernel and unmerging all the nvidia stuff and then emerging all the nvidia stuff and then putting the fastwrite options in, and when I used to get like 30fps max in ut2k3 I now get like 45 consistant and the game is much more fun.

I am back to the AGPGART based setup, it works great now.
Now to build a 2.5 series kernel

So overal I am happy.
It is 4am here, bed time :oops:

-Andrew

tirantloblanc · Posted: Mon Nov 04, 2002 4:50 pm Post subject:

Thanks for the advice, enabling "Fast Writes" made my system faster when running UT2003!!!

MotherBoard ECS K7S6A
Chipset: SiS 745
It does support "Fast Writes" and "SBA"
AGPgart: Kernel 2.4.19-Gentoo

Graphics card: Hercules 3D Prophet II MX 32MB AGP
Chipset: nvidia Geforce 2 MX
It only supports "Fast Writes"
Driver: Nvidia-latest

I haven't had any stability issue. This motherboard is superstable! and only cost me 55!!

TheCoop · Posted: Mon Nov 04, 2002 5:35 pm Post subject:

it screwed up my system, X locked up on bootup, i had to boot from the cd to change the nvidia file back...

GF4 TI4200
Epox 8KHA mobo /w VIA KT266 chipset
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Change the world - move a rock

kvh009 · Posted: Thu Nov 14, 2002 3:37 pm Post subject: Where change in BIOS?

I've got Phoenix - Award BIOS v6.00PG; I can't find any place to change the AGP Fast Writes. Fast Writes not enabled even after reboot...running 1.4 gentoo.

Any ideas? :cry:

% cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: NVIDIA
AGP Rate: 4x
Fast Writes: Disabled
SBA: Disabled

% cat /proc/driver/nvidia/agp/card
Fast Writes: Supported
SBA: Not Supported
AGP Rates: 4x 1x
Registers: 0x1f000015:0x1f000104

% cat /etc/modules.d/nvidia
alias char-major-195 NVdriver
options NVdriver Vreg_EnableAGPFW=1

tirantloblanc · Posted: Fri Nov 15, 2002 12:57 pm Post subject:

kvh009:

your m/b must support Fast writes, too:

cat /proc/driver/nvidia/agp/host-bridge
Host Bridge: SiS (unknown)
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000217:0x00000114

I didn't have any option to change in my BIOS.

squanto · Posted: Fri Nov 15, 2002 1:51 pm Post subject:

tirantloblanc · Posted: Fri Nov 15, 2002 3:00 pm Post subject:

If it says supported (for host-bridge), it is already on in your bios, nothing to change there

I was pointing that if there's no option in the BIOS, it comes enabled by default.

kvh009

It seems my MB supports both options, but I still can't figure how to turn Fast Writes on.

%cat /proc/driver/nvidia/agp/host-bridge
Host Bridge: nVidia nForce
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000217:0x00000104

% cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: NVIDIA
AGP Rate: 4x
Fast Writes: Disabled
SBA: Disabled

DarkJedi9 · Apprentice Joined: 28 Oct 2002 Posts: 204

Agh, all kinds of problems getting this working. When I do cat /proc/driver/nvidia/agp/status, it says it is Disabled. I checked dmesg and it has this in it:

Linux agpgart interface v0.99 (c) Jeff Hartmann
agpgart: Maximum main memory to use for agp memory: 439M
agpgart: unsupported bridge
agpgart: no supported devices found.

So I edited my /etc/modules.d/nvidia file to look like this:

alias char-major-195 NVdriver
options agp_try_unsupported=1

and rebooted. But I still get agpgart as disabled. Any suggestions?

col · Posted: Sun Nov 17, 2002 12:07 pm Post subject:

After I aplied the module options I get :

cat /proc/driver/nvidia/agp/status
Status: Disabled

so I dont know if its working....didnt notice any more speed.

TheCoop · Posted: Sun Nov 17, 2002 12:41 pm Post subject:

try the nvagp driver instead of the kernel agp driver
_________________
95% of all computer errors occur between chair and keyboard (TM)

"One World, One web, One program" - Microsoft Promo ad.
"Ein Volk, Ein Reich, Ein Führer" - Adolf Hitler

Change the world - move a rock

squanto · Posted: Sun Nov 17, 2002 10:37 pm Post subject:

col · Posted: Sun Nov 17, 2002 11:19 pm Post subject:

ok I recompiled my kernel removing agpgart & now I still get:

cat /proc/driver/nvidia/agp/status
Status: Disabled

In my XF86Conifg I have:

Option "NvAGP" "1" (nvagp)

Now my UT2003 frame rate is worse.....what's the deal ???

DarkJedi9 · Apprentice Joined: 28 Oct 2002 Posts: 204

I just got mine working. I compiled /dev/agpgart support as a module and put a line in my vid card section of XF86Config that reads Option "NvAGP" "3" which tells X to use agpgart and then NvAGP if agpgart isn't available. Also, and this was key, I had to do a little source editing. Here's a copy-and-paste from my post at Linuxnewbie.org

Here's how I did it. I did emerge -C on nvidia-kernel and nvidia-glx (that's gentoo talk for uninstalled my nvidia "stuff"). Then I downloaded the tarballs from Nvidia's site. Now, I can't take credit for this. A friend of my brothers at college (that's university for our friends across the pond ) told me what to do next.

Change into the directory created by unzipping the nvidia_kernel-blahblahblah tarball. Open the file os-registry.c, and go down to line 228 (I believe), and change "static int NVreg_EnableAGPSBA = 0;" so that the 0 is a 1. Do the same for line 254 (again that should be it). The only difference is it's going to say FW instead of SBA. Either way, it needs to be 1, not 0. The SBA stands for side band addressing, and the fw for fast writing, by the way. Save the file, and do make install, then change to the nvidia_glx- blahblahblah, and do make install again.

In /etc/modules.conf (or whatever file is necessary to edit said file, with gentoo changes are made to /etc/modules.d/nvidia) I need the line options agp_try_unsupported=1 because my MOBO is very new. Then in the Device section of XF86Config that applies to your vid card, add the line Option "NvAGP" "3". According to nvidia's readme, this will use NvAGP if possible, otherwise it will use AGPGART.

I set /dev/agpgart to a module in my kernel config, and I'm pretty sure I don't have it loading. The chipset on my card (VIA Apollo KT266) works with NvAGP, so I'm pretty sure I don't need agpgart anyway. I think that should be all that's needed.

Here's the full post: http://www.linuxnewbie.org/forum/showthread.php?s=&threadid=75077

Hope it helps.

wHAcKer · Posted: Mon Nov 18, 2002 5:36 pm Post subject:

works like a charm on a xp 2000+ with soltek drv5 mobo and geforce 4 ti 4200
thanks a lot mate

DarkJedi9 · Apprentice Joined: 28 Oct 2002 Posts: 204

kvh009 · Posted: Tue Nov 19, 2002 6:37 am Post subject: Benchmark for FW?

DarkJedi9 · Apprentice Joined: 28 Oct 2002 Posts: 204

For me, I "benchmark" with glxgears. I don't think it's terribly accurate, but I doubled my fps when I enable FW and SBA. No idea how just FW will affect things. Personally, I would try it. I'm sure it will help a little.

kvh009 · Posted: Tue Nov 19, 2002 7:07 pm Post subject: GLX source?

The only source file I could find for the GLX module was a .rpm

Yuck, I hate rpm... :evil:

NVIDIA_GLX-1.0-3123.src.rpm

And that appears to be binary only...no source files....Hmmmmm....

Where did you get the source code for the GLX part?