Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site uiucdcsp Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcsp!forbus From: forbus@uiucdcsp.CS.UIUC.EDU Newsgroups: net.ai Subject: Re: Any data on programmer productivity Message-ID: <3500008@uiucdcsp> Date: Sun, 3-Nov-85 14:33:00 EST Article-I.D.: uiucdcsp.3500008 Posted: Sun Nov 3 14:33:00 1985 Date-Received: Tue, 5-Nov-85 23:01:46 EST References: <526@ihwpt.UUCP> Lines: 25 Nf-ID: #R:ihwpt.UUCP:-52600:uiucdcsp:3500008:000:1522 Nf-From: uiucdcsp.CS.UIUC.EDU!forbus Nov 3 13:33:00 1985 Ahem. How many people who buy vax 780's give them to a single user? Worse still, many people who buy Suns seem to run them with multiple users, and often swapping over a network to a shared disk. The latter is a crazy idea for AI programs; while the ethernet may or may not be a bottleneck, sharing a disk between several processors certainly is! And of course, none of the Gabriel benchmarks really test paging performance, which is where non-trivial AI programs spend most of their time. Some of my students have tried to bring up programs written for Symbolics machines on Suns, and vice-versa. Factors of 15 performance improvement are not uncommon. The Suns involved were NOT Sun-3's, and the dialect was Franz, so these figures shouldn't surprise anyone. I'm quite curious to see what will happen with Lucid's CommonLisp on Sun-3's when we can try serious-sized programs. Which, thankfully, with CommonLisp we can do with a minimum of pain. Remember, however, the original question refered to lisp machines versus standard time-sharing environments. If a stand-alone 20 with PSL performs in the neigborhood of a Symbolics, then how will it do with 20-60 users? Answer: very badly! I think it is safe to say that there is NO computer on the market which runs Common Lisp (other lisps are simply not contenders at this stage of the game) which will provide for several users at once the same performance they can get if they are sitting at stand-alone workstations (be they Symbolics, Sun, TI, or Xerox).