BIOS Updates forum

Does anyone know/recall what the issue is with an Apollo Pro133A (694X) NorthBridge and an nVIDIA AGP card/chip running at 4X, AGP 2.0 mode?

There is a patch available on the VIA site to "unlock" 4X mode in the registry for nVIDIA, but from looking at the VIA Driver Release notes, 4X mode "for nVIDIA only" was removed from the chipset driver in version 4.30 (though no reason is given).

If I do a PCI register scan in DOS, I can see 4X mode available for both the chipset and video, but once Windows (XP in this case) loads, only 2X mode is available. This points me to something happening within the chipset driver.

Any help? Thanks.

I recall the registry hack:

http://www.kickassgear.com/Articles/GeForceVIA.htm
http://www.tweaktown.com/document.php?d ... iew&dId=68

...but NVidias were quite unstable at 4X in Apollo chipsets.

But, if one doesn't use the official Nvidia drivers and uses the Omega Drivers, the problem gets solved: the card is set and runs at 4X.
http://www.omegadrivers.net

The second link actually provided some useful information...

The VIA provided patch uses this key (appears to ve Win9x only)-

[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]"EnableVia4X"=dword:00000001

It seems the W2K patch is different though -

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\nv4\Device0]"EnableVia4X"=dword:00000001

In WinXP, neither of these keys is present. I can find a "Device0" under the "nv" key, but I'm not sure if this is the correct place to add the "dword" value or not.

I am assuming though that you need to set the 694X to have 4X available first...or is it if you set the video card first, the chipset will follow?

Note that this is all for a test...not to enhance any 3D gaming, etc...

Wouldn't you much rather try the Omega drivers? They're quite famous...

I know nothing about them, but I will do some research.
Thanks for the input AJZ!