It doesn't matter in which order the drivers are installed. Usually. But apparently in Ydee case the AGP problem is fixed when VIA GART driver is installed last.

The Serpent Rider wrote on 2025-11-04, 16:23:

It doesn't matter in which order the drivers are installed. Usually. But apparently in Ydee case the AGP problem is fixed when VIA GART driver is installed last.

It's difficult to install the network card driver first if it's not listed in the OS device manager at all.
I wouldn't be writing about this with such confidence if I hadn't spent half a day replacing several network cards 20 years ago.
That's why I still remember these subtleties.

In Windows 98, 4-in-1 technology almost completely reconfigures the chipset, as the VIA support implementation in the BIOS\OS build-in drivers turned out to be less than ideal.
At least in the Award BIOS.

I have to admit, I have the onboard LAN, AC97,LPT and COM disabled in my BIOS. So I don't know if the W98 would have any problem without installing 4in1 drivers if I had everything enabled, but I turn off anything I don't use.
I just wanted to write that when installing 4in1 drivers as the first software after installing the OS itself, the AGP texture acceleration was disabled and unavailable. When I installed the 4in1 package after forceware drivers were installed, the acceleration switched on and can be turned off - before the button was inactive.

Of course, I don't know if this will help solve the buggy problem every time, but I haven't had a chance to get any older versions of the BIOS (the oldest version is from 2006), changing the speed of the AGP (8x to 4x) hasn't helped, and other tips on the solution haven't worked either. The procedure described above solved the problem in my case.

Detonator most likely reads the state of the chipset registers; if it doesn't like something, it disables AGP memory.

At the time, Nvidia drivers were actively changing modes due to stability issues with VIA-based motherboards.

It would be interesting to compare Nvidia driver registry keys for different installation methods.
Perhaps we can identify key something like "AGP RAM disabled" or "Capability mode on."

Ydee wrote on 2025-11-04, 15:33:

I don't know if I've come across a one-size-fits-all solution, but I'll describe what worked in my case.
<...>

Thanks for the info. I've tried my best to replicate this on my 4CoreDual-VSTA with GeForce 5700LE. Unfortunately - no dice.

dxdiag does indeed say that AGP Texture Acceleration is enabled (was it ever unavailable on 4CoreDual?), however 3dmark2001 still says that Total AGP Memory is 0 bytes. AGP capabilities tab shows that Aperture Size is 0 bytes.

The system scores ~7300 marks in 3DMark 2001SE (Core E7600, Geforce 5700LE).

Ah well.

shevalier wrote on 2025-11-04, 16:48:

In Windows 98, 4-in-1 technology almost completely reconfigures the chipset, as the VIA support implementation in the BIOS\OS build-in drivers turned out to be less than ideal.
At least in the Award BIOS.

That's fascinating and explains a lot of the weirdness of earlier VIA chipsets. However, besides this AGP issue on later BIOS versions, the PT880 and K8M800 chipset based motherboards are perfectly happy with just Windows INF based installs. I automated viamach.inf, usb2via.inf, viamraid.inf, and viagart.inf installation on 98SE for testing purposes (infinst.exe) and all the device drivers install without any issues. I had to edit in missing registry entries to viagart.inf but that was all I had to modify. I've been able to completely avoid using the 4in1 executable. What chipset did you encounter those issues on?

The Serpent Rider wrote on 2025-11-04, 16:23:

It doesn't matter in which order the drivers are installed. Usually. But apparently in Ydee case the AGP problem is fixed when VIA GART driver is installed last.

It does matter. When researching this a while ago I found that VIA's AGP implementation was always pretty shaky and prone to not installing correctly, leading to the same symptom since the GART driver isn't present or installed correctly. The "correct" method I've read is going through the 4in1 installer's items one at a time, not all at once.

I see some of that happening in this thread too. But it's not the solution to the specific issue with VIA PT8XX and K8XXXX chipsets after the 2005 BIOS update that fundamentally broke GART in 98. Some posters are also encountering Nvidia's soft GART driver, implemented some time after 45.XX. IIRC that will show 32 or 64 MB of AGP memory in 3DMark01 regardless of what the setting is in BIOS, because it's not hardware based GART provided by the chipset. It's better performance sure, but that's also not a real solution to this issue.

shevalier wrote on 2025-11-05, 06:46:

Detonator most likely reads the state of the chipset registers; if it doesn't like something, it disables AGP memory.

I might have ruled that out last year when I compared all the registers between the known good and known bad BIOS versions, all of the chipset and GPU registers are identical.

At the time, Nvidia drivers were actively changing modes due to stability issues with VIA-based motherboards.

It would be interesting to compare Nvidia driver registry keys for different installation methods.
Perhaps we can identify key something like "AGP RAM disabled" or "Capability mode on."

I tried every flag I could find regarding VIA, AGP, or GART in RivaTuner, nothing helped this issue. Those all seemed to be for issues with older chipsets, at least that's what I gleamed from read 2 decade old forum posts. I think trying to install the GPU driver before the chipset and AGP driver could be the cause of some of those issues.

Zoomer wrote on 2025-11-05, 12:30:

dxdiag does indeed say that AGP Texture Acceleration is enabled (was it ever unavailable on 4CoreDual?), however 3dmark2001 still says that Total AGP Memory is 0 bytes. AGP capabilities tab shows that Aperture Size is 0 bytes.

That is something that should be clarified in the OP, dxdiag is not a reliable report if the bug is present or not. The most reliable way I can think of is: if AGP is properly installed and enabled in the Nvidia display settings tab:

And, like in the OP, 3DMark01 reports 0 bytes of AGP memory, then the bug is most likely present. If the AGP memory values are mismatched between the Nvidia display settings and 3DMark01, it might be because it's running a soft GART.

VDNKh wrote on 2025-11-19, 15:22:

That's fascinating and explains a lot of the weirdness of earlier VIA chipsets. However, besides this AGP issue on later BIOS ve […]
Show full quote

shevalier wrote on 2025-11-04, 16:48:

In Windows 98, 4-in-1 technology almost completely reconfigures the chipset, as the VIA support implementation in the BIOS\OS build-in drivers turned out to be less than ideal.
At least in the Award BIOS.

That's fascinating and explains a lot of the weirdness of earlier VIA chipsets. However, besides this AGP issue on later BIOS versions, the PT880 and K8M800 chipset based motherboards are perfectly happy with just Windows INF based installs. I automated viamach.inf, usb2via.inf, viamraid.inf, and viagart.inf installation on 98SE for testing purposes (infinst.exe) and all the device drivers install without any issues. I had to edit in missing registry entries to viagart.inf but that was all I had to modify. I've been able to completely avoid using the 4in1 executable. What chipset did you encounter those issues on?

The Serpent Rider wrote on 2025-11-04, 16:23:

It doesn't matter in which order the drivers are installed. Usually. But apparently in Ydee case the AGP problem is fixed when VIA GART driver is installed last.

It does matter. When researching this a while ago I found that VIA's AGP implementation was always pretty shaky and prone to not installing correctly, leading to the same symptom since the GART driver isn't not present or installed correctly. The "correct" method I've read is going through the 4in1 installer's items one at a time, not all at once.

I see some of that happening in this thread too. But it's not the solution to the specific issue with VIA PT8XX and K8XXXX chipsets after the 2005 BIOS update that fundamentally broke GART in 98. Some posters are also encountering Nvidia's soft GART driver, implemented some time after 45.XX. IIRC that will show 32 or 64 MB of AGP memory in 3DMark01 regardless of what the setting is in BIOS, because that's not hardware based GART provided by the chipset. It's better performance sure, but that's also not a real solution to this issue.

shevalier wrote on 2025-11-05, 06:46:

Detonator most likely reads the state of the chipset registers; if it doesn't like something, it disables AGP memory.

I might have ruled that out last year when I compared all the registers between the known good and known bad BIOS versions, all of the chipset and GPU registers are identical.

At the time, Nvidia drivers were actively changing modes due to stability issues with VIA-based motherboards.

It would be interesting to compare Nvidia driver registry keys for different installation methods.
Perhaps we can identify key something like "AGP RAM disabled" or "Capability mode on."

I tried every flag I could find regarding VIA, AGP, or GART in RivaTuner, nothing helped this issue. Those all seemed to be for issues with older chipsets, at least that's what I gleamed from read 2 decade old forum posts.

Zoomer wrote on 2025-11-05, 12:30:

Ydee wrote on 2025-11-04, 15:33:

I don't know if I've come across a one-size-fits-all solution, but I'll describe what worked in my case.
<...>

dxdiag does indeed say that AGP Texture Acceleration is enabled (was it ever unavailable on 4CoreDual?), however 3dmark2001 still says that Total AGP Memory is 0 bytes. AGP capabilities tab shows that Aperture Size is 0 bytes.

That is something that should be clarified in the OP, dxdiag is not a reliable report if the bug is present or not. The most reliable way I can think of is: if AGP is properly installed and enabled in the Nvidia display settings tab:

Where it says "AGP 4X" and "128 MB"

The attachment agp_nv_display.png is no longer available

And, like in the OP, 3DMark01 reports 0 bytes of AGP memory, then the bug is most likely present. If the AGP memory values are mismatched between the Nvidia display settings and 3DMark01, it might be because it's running a soft GART.

It was definitely a VIA Pentium 3 implementation from ASUS.
Most likely something on the 694 chipset.
Definitely not the MVP3, whose problems have become legendary.

As for the latest chipsets from VIA, there were no particular complaints when they were relevant.
But back then, hardly anyone used them with Windows 98.