Ray tracing software is available both for lens design and for
general optical systems modeling. It tends to be designed
to run on a single processor and can be very time-consuming if the
number
of rays traced is large. Previously, multiple digital signal processors
(DSP) have been
used to perform such simulations. This approach is attractive
because DSPs are inexpensive and the time saved through parallel
processing can be significant. In this paper we report a nearly linear
relationship between the number n
of processors
and the rate of ray tracing with as many as 839 processors operating in
parallel on the Naval
Research Laboratory's Cray XD-1 computer with the Message Passing
Interface (MPI). In going from one processor to 839 we achieved an
efficiency of 97.9 % and a normalized ray-tracing rate of 6.95 ·
106
rays · surfaces /(s · processor) in a system with 22
planar surfaces, two
paraboloid reflectors, and one hyperboloid refractor. The need
for load-balancing software was obviated by the use of a prime number
of processors.
| Return to CDR Cameron's Home Page | |
Send E-mail |