Here, I try to convey a rough idea of Triangle's speed. The times given are for the Dell PC with a Pentium II sitting on my desk. I used an executable compiled for double precision arithmetic by gcc with the -O (optimizer) switch.
I timed the Delaunay triangulation of 1,000,000 vertices uniformly randomly distributed in a square. The output contained 1,999,955 triangles. (I used the -I switch to suppress the rewriting of input vertices to another file, since the vertices written would be identical to the ones read. Hence, only the triangles were written to disk.)
A comparison of Triangle's Delaunay triangulation algorithms (done years ago on a now-old machine) is available as part of my paper on Triangle.
I also timed the Delaunay refinement quality mesh generation algorithm. Starting with a small planar straight line graph (box.poly) as input, I refined it with a very small area constraint, using the command
triangle -pqca.00001 boxThe result was a triangulation with 624,101 vertices and 1,244,077 triangles. The vertices, triangles, and boundary segments were written to disk in three different files.