NvAGP + AGP GART

[bolsh]

Hi guys,
I would love some advice. Bear with me while I give you the essentials...

I am currently running RH7.3 with kernel upgraded to 2.4.18-27.7xsmp using XFree86 version is 4.2.0 (RH 4.2.0-8).
GFX Card is nvidia quadro4 750 and I am using the 4349 drivers.

The motherboard chipset is an e7505.
I get these errors in /var/log/messages

kernel: agpgart: Unsupported Intel chipset (device id: 2550), you might want to try agp_try_unsupported=1.
insmod: /lib/modules/2.4.18-27.7.xsmp/kernel/drivers/char/agp/agpgart.o: init_module: No such device
insmod: /lib/modules/2.4.18-27.7.xsmp/kernel/drivers/char/agp/agpgart.o: insmod agpgart failed
kernel: 0: NVRM: AGPGART: unable to retrieve symbol table

In my XF86Config-4 file I have this line
# Option "NvAgp" "1"

The resultant effect is that there are spontaneous X Session restarts.
When I use agp_try_unsupported I get

kernel: agpgart: Trying generic Intel routines for device id: 2550
kernel: agpgart: AGP aperture is 64M @ 0xf4000000

The X Session no longer spontaneously restarts.


Obviously the try_unsupported resolves my issue.
My questions are:
Do I need to get agpgart to load?
I know the line in XF86Conf is commented out. I was told that by default NvAgp is set to 1. Does this mean I am currently using NvAGP?
Do I need to uncomment out the line?

I was told by my (international) vendor that NvAgp defaults to 1 so I dont need it in my XF86Conf (and the conf file they provided does not have this in it)
and I was told that NvAGP is a substitute for AGPGART so I should ignore the error messages because they dont mean anything because NvAGP is doing the job of AGPGART.

Can someone enlighten me as to what the real story is?
What settings SHOULD I be using for this card with these drivers? etc

Any advice is greatly appreciated

bolsh

[Andy Mecham]

NVAGP defaults to 3 - try AGPGART, then try NVAGP. As AGPGART is failing, you'll fall back to NVAGP. You can tell which one you're using by checking the contents of /proc/driver/nvidia/agp/status.

Your vendor was mistaken about the default setting for NVAGP, but they're correct about ignoring the warning messages. The E7505 is not a chipset that AGPGART supports - when it bails out, NVAGP loads.

--andy

[bolsh]

Thanks so much for your swift reply Andy.

I guess all I really need to know now is what you/NVidia recommends?

Is it better to just use NvAGP and ignore the agpgart error messages?

or am I better off using AGPGART, inserting it by using the agp_try_unsupported (the only way that I could insert it) ?

Am I losing functionality elsewhere by using agp_try_unsupported that wouldn't be lost by using NvAGP?

I have machines using both nvagp and agpgart for testing.
Both have:
Fast Writes: Disabled
SBA: Disabled

Is there any benefit to enabling these for 3d modelling/animation (or for any other reason)?
If so, how do I enable them?

Im sure this is documented somewhere but only having seen them you can probably save me the time :)

Thanks so much again

Bolsh

[rohitntu]

Hi Andy,

Could you please advise how I can enable SBA and Fast Writes on the E7505 chipset? The latest 4363 driver did not help. I'm using NvAGP I believe.

I am seeing very poor performance with glCopyPixels, I'm using Quadro 580 XGL. (glDrawPixels seems to be fast enough)

Please advise.

Regards,
Rohit