Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!elroy.jpl.nasa.gov!decwrl!pa.dec.com!bacchus!mwm From: mwm@pa.dec.com (Mike (My Watch Has Windows) Meyer) Newsgroups: comp.sys.amiga.programmer Subject: Re: Virtual memory for Amiga! Message-ID: Date: 1 Apr 91 18:30:07 GMT References: Sender: news@pa.dec.com (News) Organization: Missionaria Phonibalonica Lines: 30 In-Reply-To: holgerl@amiux.UUCP's message of 31 Mar 91 18:53:09 GMT In article holgerl@amiux.UUCP (Holger Lubitz) writes: Tricky. And if you ever run out of real memory so that the OS starts placing YOUR PROGRAMS in virtual memory, be prepared for a severe performance loss. As opposed to what happens when you run out of real memory with no VM. If you're real lucky, you've got a well-written application that will pause while you find out if you've got enough memory get to a window and run a delete to make disk space to save things into. More likely, you get to start finding bugs in your application, and the OS. Paging/swapping is a "fail-soft" option. It takes you from not being able to perform a task, to being able to perform a task at a reduced rate of speed (when compared to useing real memory). The cost is a degredation in speed right at the edge of failure (*), and that's it. VM is a tool. Like any other tool, VM used wisely can save you time and/or money. Used badly, it can make your life miserable. I know I've got a number of tasks that don't fit on my system.