Setting up bios on Asus P2B motherboard

[PDFM]

I have recently installed a matrox G400 dual head 32MB card on my Asus P2B
motherboard system (pentium II 333), and am trying to optimise the settings.

(1) Parity/ ECC problem

I have seen advice from Matrox technical people to set the motherboard bios
to NON_ECC. Is this required and why? Has any Asus bios update dealt with
the problem?

(2) AGP aperture size

My P2B handbook says to leave the "graphics aperture size" at default
setting of 64MB, but Matrox says the "AGP aperture size" should be 256 MB.
Are they talking about the same thing, and should I increase the aperture
size? Is this only for pentium III chips to get advantage of Turbo GL?

(3) Video Memory Cache Mode

Does the G400 support this feature? Should I activate it

(4) VGA bios sequence

This is currently set to PCI/AGP - should it be set to AGP/PCI?

(5) Sharing IRQs

The display adapter is sharing IRQ 11 with the PCI to USB universal host
controller. Usb is not used on my system. Is this sharing likely to be a
problem?

(6) Latest patches for chipset/AGP

The chipset is Intel 440BX AGPset. Are there new patches? Do I need them?
Where do I get these?

(7) DCC and vbext.exe

I've got a Mitsubishi 900u diamond pro 19" monitor. When I loaded the original Matrox system utilities from the CD with the card, it added the vbext.exe line to the autoexec.bat and the start up messages now told me that I had a DCC compliant monitor and the display is using optimised settings from the monitor. When I did a complete driver clean out in accoirdance with the configuration FAQ, in order to load the latest 5.41 drivers, vbext.exe was not reloaded. The question is - what is DCC and how do I use it? Do I need vbext.exe, and should I reload the original system utilities from the CD?

For any help, many thanks!

Peter

[xortam]

Jorden, I have a G400 Max running on an ASUS P2B-S with a PIII/450. I was wondering about your statement "Set the Video Cache Mode to USWC". Have you noticed any effect on performance or stability when changing this option? I'll have to check but I believe I'm running with it set to "UC".

[PDFM]

Hello Jorden,

Thanks for your detailed reply, and the additional matters.

Peter.

[Jorden]

xortam, the USWC (uncacheable, speculative write combining) should speed up the display speed by caching the display data. Or so it says in the manual. To be honest, I haven't noticed any speed-increase. It did make my video more stable, though.
Maybe someone else found a speed-increase?

Peter, you're welcome

Jord.

[This message has been edited by Jorden (edited 16 January 2000).]

[xortam]

Jorden, Sure enough. I had mine set to "UC". I've switched it over to "USWC" and we'll see if it makes any difference. I will get a lockup every few days (at most) that reminds me of when I had a bad Max that I had to return. I guess now I'm inclined to benchmark the two settings.

[xortam]

Well I got the same Quake 3 benchmarks with both settings. Compared 16-bit and 32-bit, bilevel, mid quality setting as well as 16-bit and 32-bit, trilevel, high quality settings. No differences. The first time I booted with the "UWSC" setting, the second benchmark hung (demo002). Everything ran fine on second boot. The verdict is still out on this BIOS setting for me.

[Hunsow]

(1) Dunno

(2) Do some thinking, of course it's the same thing. Try 256Mb first, if something runs unstable or slow, try a different setting.

(3) Turn it OFF! Turn of all bios caching and shadowing.

(4) With just one videocard in the system it doesn't matter.

(5) There is probably a 'Assing IRQ to USB' option, set it to NO.

(6) The nice thing about an intel system that it doesn't require any patches, allthough there is a .inf file update, but you don't really need it.

(7) If you don't use DOS you don't need vbext.exe, delete the line in the autoexec.bat if this is the case.

[Jorden]

Hi PDFM,

Here's some answers
[list=1][*] The Parity/ECC is for the main RAM. Not for the videoRAM or anything else. If you have ECC SDRAM (a little chip on the SDRAM checks the RAM constantly and repairs errors), you'd set this one enabled. If you enable it, but don't have ECC RAM, no harm's done, all will work
[*] AGP aperture size is the same as the P2B graphics aperture size. Set it to 128 or 256Mb. What it does is use all the remaining available RAM memory from your PC for temporarily storing large textures in. Someone else can explain it better I bet
[*] Set the Video Cache Mode to USWC. Yes, the G400 supports this option.
[*] Set VGA BIOS sequence to AGP/PCI. It will then take priority on an AGP videocard in your system.
[*] If you don't use USB on your system, you can shut it down. (In PnP and PCI Setup, disable USB IRQ, freeing that IRQ for your G400 only.
[*] No, there are no updates on the mobo, in the way of drivers. You can get the latest BIOS here
[*] DCC means that your monitor will be sending a signal to the videocard/PC when it's on, saying as much as "Hello, I'm a monitor, this brand and that size, which resolutions can you give me?". Upon which your videocard and PC (and Windows) knows what monitor hangs onto your PC and what it can do.
The VBEXT.EXE is only needed when you play games in DOS, as this file contains some resolutions that aren't in the drivers itself. You do not need to reload the original drivers when you use PD5.41 for these drivers support the other resolutions as well.
[*] Somethings you overlooked
In the BIOS menu BIOS Features Setup, set Video ROM BIOS Shadow to disabled.
In PnP and PCI Setup set the Slot 1 (Right) to IRQ 11. Now you know for sure that only your AGP port is using IRQ# 11. Do leave the PCI slot next to the AGP port empty (if possible).[/list=a]

Good Luck

Jorden.

[PDFM]

Thanks for the quick reply. Sorry about the dunb nature of some of the questions. I've never had to get to grips with the world of PC graphics before.

Peter

[SCompRacer]

PDFM,

I have seen advice from Matrox technical people to set the motherboard bios
to NON_ECC. Is this required and why? Has any Asus bios update dealt with
the problem?

The initial G400 drivers had a problem with the ASUS P2B series motherboards with ECC Memory installed and ECC Enabled. With the first driver release, OGL app's would crash with ECC Enabled in BIOS. Disable ECC and life was good again.

The second driver release and up fixed this problem and it has not bothered me since. The P2B series was the only MB affected by this that I am aware of.

Could be Matrox takes no chances since it was an issue once and continues to recommend it.