A heatsink will greatly expand the surface where the heat can be taken away from by a fan...
It makes a fan way more effective then it just blowing at the bare chip. Just something to think about.

At a Pentium 166MMX, you’re not going to push the Voodoo2 hard enough to warrant an exotic cooling setup. General best practices will suffice. Allow good case air flow, and if you can point any old fan as extra insurance in its general direction you’ll be fine.

I have a voodoo2 in SLI, set up combined with a MMX 233, in a closed case with no fan in it besides the one in the power supply and the one on the CPU, gaming while it is 31C outside on the attic. The voodoo2 doesn't get any higher than 62C while it is 33C inside the house.

I would not consider going trough the hassle of cooling these cards, let alone doing it on a Pentium which runs 66Mhz slower than the one I am using.

Playing Deus Ex on a Athlon XP2400+ 2GHz on these cards the other hand, resulted in a crash after 2 hours of gaming since the bottom card ceased to function due to the heat. I have put a in house fan on it due to the extreme temperatures at the attic at the moment, otherwise I wouldn't even consider cooling this setup either. Normally it will go as high as 71C when it is 20C in the room.

When Voodoo 2 were new I went through my original board and a replacement from 3DFX that got fried by overheating in my Pentium 200 MMX. These cards can absolutely be destroyed by slower hardware. On the second replacement they sent me I purchased a fan to blow across the chips, not into them, and that fixed the issue.

Meatball wrote on 2022-08-12, 12:08:

At a Pentium 166MMX, you’re not going to push the Voodoo2 hard enough to warrant an exotic cooling setup. General best practices will suffice. Allow good case air flow, and if you can point any old fan as extra insurance in its general direction you’ll be fine.

That's a good point, and I'd be happy with that.
@Shagittarius: could it have been a manufacturer issue with your first card?

So far, I'm done with my Pentium MMX 166 build, 128MB RAM (I know, it's overkill), SoundBlaster 16 Ct2890, S3 Virge DX/GX, and a Creative Labs 3D Blaster Voodoo2 (found it for a good price, otherwise I'd go for a Voodoo 1)...if not that I thought about cooling the Voodoo when I was about to install it 🤣
I've done a couple of tests and so far it was ok, I have to confess that I'm still on the fence for this tho.

128mb is actually literally slowing your performance. I have a 11% performance hit if I go from 64 to 128mb memory on the mmx 233.

And voodoo 2 can run almost every Glide dos game and run the windows games in 800x600 if you would like with z buffering enabled. For example nfs3.