I've got a 333mhz k6-2 (overclocked to 350) and a Diamnond V550 TNT on an AOpen AX59pro motherboard (VIA MPV3 chipset). Although lots of people like saying that the TNT won't work with socket7 or that it won't work with an AMD cpu, don't believe 'em!
Just make sure that you get hold of the latest motherboard and AGP chipset updates and you'll have no problems.
Just for the record, Quake2 demo1 runs on my PC at 42 fps (1024x768, openGL, full colour).
Damn straight it rocks. On Tom's hardware guide, a K6-2 350 (V2 card using 3dnow drivers) is equal to a PII 400 at 640x480 running crusher and demo1. At 800x600, the same K6-2 system beats the PII 400 in both benchmarks and ties with a Celeron 450A.
The "low end" K6-2 300 is also within 2fps of a PII-400 (when using 3dnow) for both crusher and demo1 at 800x600.
Since I haven't seen benchmarks for K6-2 400 running quake, I knocked up an estimate by extrapolating the framerates. The diminishing effect of L2 cache should be easily offset by the improved core of the 400. Using this estimate, the K6-2 400 looks like it will beat a Celeron 450A system by a slim margin at 640x480 and a wider margin at 800x600.
These benchmarks are using the V2, since I don't have any 3dnow figures for the TNT, but the TNT is slightly faster on a V2 without 3dnow, so I expect figures to be very similar with 3dnow drivers (probably better, owing to the TNT's hunger for CPU power).
What is the current situation with TNT and 3DNow? I think the latest nvidia reference drivers support it, but don't hold me to that
At any rate, K6-2 users will find increasingly good performance as more titles and drivers come out with 3dnow support. Quake 2, Unreal, Sin, Incoming etc etc all apparently support 3dnow, and you can count on titles in the future using 3dnow instructions. I can't wait to get my hands on a new K6-2 system (less than a month to go... yay). I'll be going for a TNT as well.
I just bought the AGP Viper 550 and it installed without a problem, win98 found it, the only problem USE THE NEWEST DRIVERS. The driver that came with it gave me nothing but a blank screen. If that does happen switch to standard VGA and reinstall new drivers...