Yet some more comparison material.

Asus P5A-B (1MB cache), 128MB pc133 cl2@100MHz, K6-3 @400, Diamond V770 TNT 2 agp.
3d mark 99 stock settings: 3330 / 6544

Asus P5A-B (1MB cache), 128MB pc133 cl2@100MHz, K6-3 @400, nameless TNT 1 agp.
3d mark 99 stock settings: 2393 / 6429

PC Chips M577, 64MB pc100 CL3, K6-2@500, Asus V3800 (TNT2)
3d mark 99 stock settings: 1895 / 4791

Gigabyte GA-5AX r3.0, 256MB PC133 Cl2 @100, K6-3+ @550, Asus V3800 (TNT2)
3d mark 99 stock settings: 3386 / 7850
3D mark 2000 stock settings: 1584 / 83

Its been a lot of reading. Swapping out motherboards has been a bit of a mixed bag. The biggest performance gain I got was by tweaking the bios specifically the Chipset Features screen. Changing these settings led to a +5 fps boost in Quake III (39fps) which was still on the low side. So noticing the increase in cpu performance but a drop in 3D performance I searched around and found K6-III+ 450 fastest overclock where skyscraper and phil both mention a drop in performance with Voodoo3 PCI cards specifically. I can say I experienced the same here. If anyone ever found a solution to that problem let me know.I think I'll continue on tinkering but I'll post in the system specs thread. I got a good baseline from the posts here thanks to all who posted. The results I gathered are collected in the attached spreadsheet: https://drive.google.com/file/d/1FgbvZnPomuFF … iew?usp=sharing

(.ods is Libreoffice, Excel should be able to open this)