n3f v3f timing

[Dr. Michael M. Cohen]

Query on the temporal characteristics of the n3f v3f calls:
Do these return to the main program only after transfer is
complete or are they asynchronous in the sense that they just start
transfer and next call will wait if the hardware is not ready?
My situation is that for about 1k polygons, it's taking about
10 msec to compute the normals followed by about 10 msec to
send the polygons. If the vertex sending calls are asynchronous
perhaps I can interleave the normal calculations with the
n3f v3f calls to do the job in less than the 10+10 msec it's now
taking... If anyone has assembly language routines for computing
polygon and vertex normals more efficiently than what the c
compiler can produce, I'd be real interested in taking a look!

TIA for any answers/pointers, MMCohen
[system is 4D310VGX-FX 3.3.2 16mb]