VOGONS


First post, by Bruno128

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First things first: only comment here with firsthand evidence in a short and concise manner. Don’t speculate or ask if a motherboard will or will not have this problem. If you made any progress, send a PM, the post will be updated.

Preamble: this thread is to collect scattered anecdote of a problem collectively known as "VIA 0 bytes AGP memory bug" or "VIA AGP GART bug". It is relevant if:

  1. You are running 98 / ME.
  2. You are using a VIA chipset motherboard from mid-00’s.
  3. You are using an AGP card. Both NVidia and ATi are known to have this.

The bug manifests itself in low 3D performance and was introduced with BIOS updates at some point in year 2004. As of writing it cannot be solved definitively by altering BIOS settings or downgrading a driver.

How to check:
Open 3Dmark2001SE system info window, and look for “Total AGP memory” value. If it is 0 bytes you got the bug.

Example on VIA PT880
0mb agp.jpg

Known half-solutions:

  1. Downgrading BIOS (some motherboards).
  2. Cross-flashing BIOS (some motherboards).
  3. Running XP.
  4. Using ForceWare versions from 61.76 and newer as they have a partial workaround.
  5. Just use non- VIA-based motherboard

Confirmed affected motherboards:

Further reading:

P.S. If this piece of puzzle is ever solved, it is a step ahead in terms of pushing the limits with Win98 builds. Thanks for cooperating!

Now playing:
The Dig: 1995 VLB 486
Arcanum: 2003 Acrylic build


SBEMU compatibility reports list | Navigation thread

Reply 1 of 6, by Latiodile

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i have an MSI K8MM-V that has this bug, oldest bios version dates 2005 so i can't downgrade to a version that doesn't have the bug
the chipset is a via K8M800, installing windows XP doesn't fix it on this board either

Reply 2 of 6, by Dothan Burger

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I have a K8V SE non Deluxe that has the bug and I can't find a suitable Bios or Afudos that will let me flash backwards.

Reply 3 of 6, by DudeFace

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I've just checked one of my via boards for this, its an MSI PM8PM-V, MS-7222 Ver2.0, no problem on bios version 3.3, just updated to latest bios Ver 5.5, again all ok no bug.

Reply 4 of 6, by ShyShutterbug

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Hi,
can't confirm the bug on an Asus K8V MX/S board with a VIA K8M800 chipset.

My setup:
Athlon 64 3400+ Clawhammer
Radeon 9500 64 MB with a universal AGP key - Catalyst 6.2
2 GB DDR SDRAM (Thank you, Mr Loew!)
BIOS version: 08.00.09, revision 1008.010, build date 05/12/05
Windows 98 SE

The system scored over 11 000 3DMarks in 3DMark2001SE, which is AFAIK acceptable. The AGP memory size is correctly displayed in 3DMark's information box.
Cheers!

Reply 5 of 6, by xelizor

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ShyShutterbug wrote on 2024-04-22, 21:21:
Hi, can't confirm the bug on an Asus K8V MX/S board with a VIA K8M800 chipset. […]
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Hi,
can't confirm the bug on an Asus K8V MX/S board with a VIA K8M800 chipset.

My setup:
Athlon 64 3400+ Clawhammer
Radeon 9500 64 MB with a universal AGP key - Catalyst 6.2
2 GB DDR SDRAM (Thank you, Mr Loew!)
BIOS version: 08.00.09, revision 1008.010, build date 05/12/05
Windows 98 SE

The system scored over 11 000 3DMarks in 3DMark2001SE, which is AFAIK acceptable. The AGP memory size is correctly displayed in 3DMark's information box.
Cheers!

Which chipset driver version are you using? I think that last time I tested, 1008 was giving me the AGP bug on mine...

Regards

Reply 6 of 6, by ShyShutterbug

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Chipset driver: VIA Hyperion Pro V521A
ACPI is on, FDD, serial and parallel ports disabled (I've disabled those to free up some IRQs for a Yamaha YMF724 soundcard)
All USB ports enabled, USB 2.0 driver version: VIAUSB2V270-L-M

I was actually quite surprised to see it work, considering many dramatic reports here 🤣 Since you got different results, I'll see if I can reproduce the bug by any simple tweaks.

Cheers!