I ran into a strange problem: after replacing P133 with K6-2 300 on an otherwise identical system (Zida 5SVA rev.1.2 with latest BIOS 1.41, VIA Apollo VPX, 128MB SDRAM, Rage LT Pro 8MB, W98SE) crashes 3DMark99 into the desktop. With Pentium it will go absolutely without any problems, with K6 after clicking on "Benchmark" the screen goes black and then the desktop jumps back on. The K6-2 300 is functional, on another board with SiS chipset the 3DM99 also passes without any problems, no other changes in the system occurred - only CPU exchange and voltage and frequency configuration.
The only problem is the maximum multiplier 3.5x for this board revision, so the K6 runs at 233MHz instead of the nominal 300MHz, but I don't think this should cause falls. The memory benchmark in Sandra is also oddly weaker than with the slower Pentium, which amazes me.
I thought the K6 would be a nice upgrade for this machine (it runs steadily up to 400MHz thanks to the remapped 2x/6x multiplier) and the board can also do 75 and 83MHz FSB, but I'd like a 100% stable machine and it doesn't look like it with AMD.
I don't remember the time of K6 (I had Pentium then), so I don't know if any patches were needed to properly run AMD CPUs on VIA chipsets? Or for 3DM99? Or maybe it's just a rare incompatibility of the board, CPU and 3DM99?