View Full Version : Via AGP Controller and Forceware 75 problem

09-12-05, 12:08 PM
Hi, anyone having problems with a via mobo chipset and the 75 release of forceware? I have a xfx6800GT, A64 2800+, Asus K8V-X mobo (via K8T800), 2x512 mb ram, 380WAntec Truepower psu, Seagate 120gb SATA hd, and samsung dvdrw/cdrw combo.

When I installed the latest forceware drivers (78.01) onto my new Asus K8V-X motherboard, the AGP controller is ignored and my 3mdark05 score went from 4600 to 2000.

The release notes state:

VIA and ATI AGP 3.0 Chipsets
The use of AGP-protocol cycles for coherent access to regular system
memory results in data corruption on systems based on VIA and ATI AGP
3.0-compatible chipsets.
AGP-protocol cycles to the AGP aperture are not affected.
To correct the data corruption problem, the Release 75 driver exclusively
uses PCI-protocol cycles to access regular system memory when it detects a
VIA or ATI AGP 3.0-compatible chipset.

For now I've had to uninstall the 78.01 drivers, uninstalled the via agp driver (and reinstalled it) and installed the 66.72 drivers from guru3d.com. These are working well.

Is there anything I can do to make these new drivers work with with the AGP controller and not use pci protocol cycles?

Thanks for any advice you can give.


09-12-05, 12:43 PM
I haven't noticed any issues with the series 75 drivers on my board with VIA AGP 3.0. Is that issue specific to the K8 (Athlon 64) processors?

09-12-05, 01:01 PM
Hi rewt, thanks for the response. I don't think so, but I think it might be isolated to the Geforce 6 series of cards. Would that make sense?

I've visited other forums and posters have outlined a very complex series of installs and uninstalls to get the new drivers to work with the via agp 3.0 controller(install a generic microsoft agp driver after uninstalling the via - but it only works on a clean install of windows xp sp2 etc...).

All of these posters had a geforce 6 series card. I don't know why the 6 series would have a problem with via's agp controller.

I just wish the driver would give the user the option of whether or not they want to pass through the pci protocol exclusively...


09-14-05, 08:47 AM
There have been warnings about using VIAs AGP driver for months, I would personally roll back the AGP driver to the OS Microsoft one, and I bet your problem is resolved.

09-14-05, 12:07 PM
Thanks Peoples-Agent. However, I can't figure out how to roll back to the microsoft one. Is this available only with SP2 (I haven't installed SP2)? When I go to device manager and uninstall the via agp driver, the list of drivers to install are all via controllers. Do you know if the the MS driver shows up under another name? I'll investigate some more tonight to see if I've missed something.


09-20-05, 08:48 AM
It seems the 6800's have problems with all AGP drivers especially nVidia's NF3!

09-20-05, 09:45 AM
Yup I've heard of people swapping their NForce3 mobos with KT800 ones because of problems with the NV4x chips.

I'd also steer clear from the latest VIA driver updates as it seems that the basic drivers provided with Windows XP (and updated with each service pack) do a much better job.