Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!crdgw1!barnett From: barnett@grymoire.crd.ge.com (Bruce Barnett) Newsgroups: comp.sys.mac.system Subject: Re: PPC, IAC, and True Multitasking (tm) Message-ID: Date: 22 Aug 90 10:31:20 GMT References: <1990Aug3.040513.14844@d.cs.okstate.edu> <2760@bridge2.ESD.3Com.COM> <13888@cbmvax.commodore.com> <3474@tellab5.tellabs.com> Sender: news@crdgw1.crd.ge.com Reply-To: barnett@crdgw1.ge.com Organization: GE Corp. R & D, Schenectady, NY Lines: 25 In-reply-to: kenk@tellabs.com's message of 21 Aug 90 12:19:14 GMT In article <3474@tellab5.tellabs.com> kenk@tellabs.com (Ken Konecki) writes: > >If anything, a preemptive operating system will be faster, because it will > >perform task switching only when necessary. > > Apparently you have never used a Sun. There have been countless times that > I have pushed ye olde mouse button and waited for *seconds* for the > wonderful preemptive OS to respond to the input. And I'm not the only > one making this complaint. Don't confuse context switching with swapping. All Sun's have hardware registers to support 8 context switches. If you have waited seconds, it is because your process was swapped out to disk and had to be read back into memory from remote disks. Most Sun's are effectively running diskless. A somewhat equivalent Mac configuration would be running System 7, 32 megabytes of virtual memory, and all executables mounted through AppleShare or TOPS volumes. If the Sun was diskless, then the equivalent Mac configuratioon would be floppy based. I recall context switching taking more than a few seconds with a floppy based Mac running Finder. :-) -- Bruce G. Barnett barnett@crd.ge.com uunet!crdgw1!barnett