Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site cvaxa.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!gatech!seismo!mcvax!ukc!warwick!cvaxa!aarons From: aarons@cvaxa.UUCP (Aaron Sloman) Newsgroups: net.arch,net.ai Subject: M68020 and SUN3 Message-ID: <166@cvaxa.UUCP> Date: Sat, 9-Nov-85 15:28:48 EST Article-I.D.: cvaxa.166 Posted: Sat Nov 9 15:28:48 1985 Date-Received: Tue, 12-Nov-85 03:59:33 EST Organization: Univ of Sussex, Cognitive Studies, UK Lines: 44 Xref: watmath net.arch:2074 net.ai:3093 Xpath: warwick ubu I've seen much discussion of relative merits of processors in netmail, but very little on M68020. This surprises me, in view of our recent experience. SUN Microsystems lent us a SUN-3 for a few days to see if we could port Poplog to it. Some changes from the SUN-2 version were needed, but then it ran, essentially using only the M68010 compatible instructions. In spite of that we found a three fold speedup, and although we did not have time for exhaustive testing, pretty conclusive evidence that it outperformed a VAX-780, for instance. Here are our Prolog 'naive reverse' test results, to illustrate: SUN-3 (UNIX 4.2) 9500 LIPS GEC-63 (UNIX V) 6140 LIPS VAX 780 (VMS) 5360 LIPS SUN-2 (UNIX 4.2) 3210 LIPS VAX 750 (UNIX 4.2) 3000 LIPS (with Systime accelerator) Each is the best time of several runs on a single user machine, without garbage collection, so is only partly representative of actual performance. This 'quick' port was done by Jonathan Laventhol who estimates that if we did it properly, using the new M68020 instructions, there would be a substantial reduction in the size of compiled programs, and a further speed-up, possibly up to a factor of 5 times SUN-2 instead of only 3 times. This is because a lot of groups of three instructions would be replaced by two. Even without this, however, we were very impressed by the performance. Of course, we can say nothing yet about reliabilit, etc. The machine we were lent was a 4Mbyte SUN-3 with 71 Mbyte disk, two RS232 ports and a tape cartridge. It looks as if we can begin to expect performance comparable to (e.g. Symbolics) on a cheaper machine. I am very impressed, and it looks as if Motorola (and SUN) have produced a real winner. I presume Quintus Prolog, Lucid Common Lisp, etc. etc. will all experience the same speed-up. Aaron Sloman, Cognitive Studies Programme, University of Sussex, Brighton, England. -- Aaron Sloman, U of Sussex, Cognitive Studies, Brighton, BN1 9QN, England uucp:...mcvax!ukc!cvaxa!aarons arpa/janet: aarons%svga@uk.ac.ucl.cs OR aarons%svga@ucl-cs