Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!cbatt!ucbvax!dww@seismo.CSS.GOV@stl.stc.co.uk From: dww@seismo.CSS.GOV@stl.stc.co.uk Newsgroups: mod.computers.vax Subject: Re: VAX instruction timing Message-ID: <8701310733.AA28662@mcvax.cwi.nl> Date: Fri, 30-Jan-87 17:09:05 EST Article-I.D.: mcvax.8701310733.AA28662 Posted: Fri Jan 30 17:09:05 1987 Date-Received: Sat, 31-Jan-87 20:28:27 EST References: <8701100344.AA11320@ucbvax.Berkeley.EDU> Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: David Wright Organization: STL,Harlow,UK. Lines: 16 Approved: info-vax@sri-kl.arpa In article <8701100344.AA11320@ucbvax.Berkeley.EDU> SYSMGR%UK.AC.KCL.PH.IPG@AC.UK writes: >... >Where programmers can score is by improving their algorithms, ... Very true. I remember a programmer asking permission to use assembler language when I ran a "No assembler except in emergency" rule, because his 1.5mSec rate interrupt program ran for 2mSeconds. A better algorith (still HLL) took 150uSecs. For even better examples, read Knuth! >Incidentally ... is probably equally true of any other virtual memory system. >MIPs are a waste of time for everybody except salesmen A company we work with use Ridge (UNIX) and VAX (VMS) computers. The Ridge (I don't know which model) is supposed to have twice the CPU performance of the VAX (a 785). For most of their CPU-heavy simulations this was so, but for the biggest the VAX was several times faster, simply because it could handle paging of large virtual memory space with far less page faults.