smh@mit-eddie.UUCP (Steven M. Haflich) (11/28/84)
Now that folks have begun accumulating real experience with the 11/73 I'd like to hear if anyone can provide any benchmarks or even fuzzy impressions of its floating point speed. With good reason, DEC is unwilling to release "instruction-timing" numbers. These are usually meaningless anyway (compare the 11/45!) because the overhead times for communication between the FPP and the rest of a system can be significant and very difficult to calculate. My group is considering inexpensive networked 11/73 engines as downloaded processors for some venerable production signal processing code still running on an expensive PDP11/45. Fixed-point comparisons are easy to come by, but the code in question makes *extensive* use of floating instructions. Typical code has up to a 50% mix of floating op codes, frequently hand intermixed with non-floating ops to take advantage of execution overlap on the 11/45. I'll summarize to the net. Steve Hafich {ihnp4, decvax!genrad}!mit-eddie!smh