I can try with a Millennium and my DFI P5BV3+ machine. I'll go dig it out of storage.

Thanks Paradigital, I have not tried a DFI Mobo. So far I have tried two different Tyan's, Two different Epox, and two different FIC boards. You will need something that tells you the AGP transfer speed. I use SiSoft Sandra 2001 edition. So far all of them show AGP 2x speed until I install the drivers.

This was actually a pretty common thing during the SS7 era. Once video card manufacturers realized that VIA and Ali chipsets have major AGP issues (particularly @ AGP 2x), they added driver functionality that permanently locks the AGP speed at 1x on these chipsets. I'm guessing that they received a lot of phone calls from unhappy customers that were blaming the video cards instead of the platform itself. 😁
I actually consider this a feature, not a bug! 😀 There were multiple instances (with older nVIDIA drivers) where I had to dig an old VIA driver like v4.17 in order to get a fixed AGP 1x speed 😀
Anyway, I did many tests on SS7, and unless you are trying to beat any records (i.e. you want any extra frame that you can get), AGP 1x is virtually identical to AGP 2x performance. On the other hand, AGP 1x is usually very stable, while AGP 2x is a pain. My advice: don't bother! 😀

Thanks for the info Bloodem. I was aware of the problems with VIA's early chipsets and AGP but I wasn't aware that some manufacturers had actually locked 1x into the drivers but that would certainly explain my issue. And for all the talk about the problems, I have been able to get all my systems running stable with AGP. I haven't had that many problems. I have found that the boards can be a little card finicky and driver picky but once I find the right combo they work fine with AGP.
I build era specific, meaning I don't try to put a 2005 graphics card in a 1998 system and I also have a very specific load/set up procedure and I usually don't have any problems. Everyone seems to have their favorite drivers and for me I use the VIA 4 in 1 4.38 chipset drivers. Most folks seem to recommend the 4.35 version but I remember reading somewhere that the 4 in 1 4.38 was the last version written specifically for Win98, the versions after that up to 4.43 were written for WinME , then when they changed the name from 4 in 1 to Hyperion, Hyperion drivers were written for WinXP and the more advanced chipsets like Apollo Pro, KT133 and KT266. They were supposed to be backwards compatible but they were not written specifically for the old chipsets and could be problematic.
Ooops, forgot to say all my test systems are running Win98SE and the CPU's are K62-500's and I have been able to get other brands of cards to run AGP 2x without problems. You're probably thinking "why don't I just use one of those other cards?" Because my absolute favorite retro gaming rig is a Matrox G400 + Dual Voodoo2's !