To straighten things out here :
Hidden Surface Removal
is performed to some extend by a variety of 3D Engines (but AFAIK only in a limited way, since HSR costs valuable Engine runtime as well).
When implemented, it needs to be effective enough to remove large amounts of unneeded Geometry, yet fast enough in order not to kill off the performance gained.
The 3dfx Driver HSR only worked with the Quake3 Engine as far as I remember, which indeed was making things alot (!) faster, but resulted in notable, upto
severe display corruption, rendering is effectively unusable (felt like being an experimental, early Beta Stage).
If the Engine did not support HSR by the Driver, no effect was noted at all.
(e.g., run Quake3 with Aggressive settings to completely screw up the Display, then Unreal Tournament via OpenGL, and observe it having NIL effect).
And if you don't know Hank and his abilities....
...well...
From what I've heard, he's a former 3dfx Engineer, created the latest Voodoo5-6000 Hardware Fixes, and to my best knowledge is the only person existing that is able to upgrade V5-6000 Boards to the latest Version or even repair damaged ones.
Without him, many of the existing, recent Reviews would have been impossible, and would have rendered the V5-6000's as partly/largely non-functional Prototypes they originally were.
Hank is likely indeed the man to talk to, when it comes to separating what might be possible in Software, and what would need to be fixed/modified in Hardware (out of reach for Software workarounds)