From what I’ve read the Voodoo3’s have poor alpha blending performance. There only seems to be one option in the driver settings for it, you could try seeing if Smoother vs Sharper has any impact. You would have better luck seeing if SHOGO or HG2 have any graphical tweaks related to smoke or alpha blending.

I've noticed massive slow downs with most cards from this era when there is detailed smoke in a scene. The first narrow hallway in the first level of Descent 3 basically brings any pre-Geforce to its knees at anything over 800x600. And you're right, it feels more like slow motion than low frame rate. I remember this being normal back in those days. Someone with more knowledge of rendering and graphics could probably explain what makes a game slow down this way versus just getting choppy. Also, I think Descent 3 even used Glide so I don't believe it is totally API dependent.

Yeah, I've noticed that in Descent 3 as well... as it's pretty hard to miss, sadly. The reason why I was suspecting it might be user error (settings, etc) is that it's pretty weird to have a game that predates the card's release by a year or two performing so poorly on hardware that was supposed to be superior to anything available on the market when the game hit the shelves. The worst offender is the SloMo effect. I would take choppy over swimming through tar any day of the week, at this seriously throws your aim off.

Btw, I did experiment with alpha blending setting in 3dfx Tools, but saw no improvement on any setting. At least in HG2 I was able to mitigate it (somewhat noticeably) by lowering shadow and effects quality (which pains me greatly), but while playing Shogo I couldn't find any configuration that would help (other than lowering the resolution) so I just soldiered through the entire game @1024, despite the slowdowns.

I guess that was just a sign of the times back then. Oh well, I wanted the genuine experience so I willembrace it. It still beats having to finish Half-Life 1 and a multitude of other games on 166MMX with Voodoo 1 while playing @512x384 and barely getting 30FPS. Despite the performance problems, playing those games now using era-accurate gear (including ball mouse) is somehow infinitely more satisfying than playing them in 1080p on i7 via 3dfx emulation and that sort of trickery. And nothing can emulate those 3dfx slightly washed out visuals and dithered transparency you get from the real thing. Brings back all the feels 😉