Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site mit-eddie.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!mit-eddie!smh From: smh@mit-eddie.UUCP (Steven M. Haflich) Newsgroups: net.unix-wizards Subject: Floating point benchmarks for 11/73? Message-ID: <3201@mit-eddie.UUCP> Date: Wed, 28-Nov-84 07:07:56 EST Article-I.D.: mit-eddi.3201 Posted: Wed Nov 28 07:07:56 1984 Date-Received: Thu, 29-Nov-84 05:54:10 EST Distribution: net.unix-wizards Organization: MIT, Cambridge, MA Lines: 20 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