Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!linac!att!ucbvax!FANDM.BITNET!NJ_GOKEMEIJE From: NJ_GOKEMEIJE@FANDM.BITNET Newsgroups: comp.sys.amiga.advocacy Subject: re^4:what to buy??(numbercruncher) Message-ID: Date: 19 Jun 91 16:01:00 GMT Sender: daemon@ucbvax.BERKELEY.EDU Lines: 41 From: IN%"melling@cs.psu.edu" "Michael D Mellinger" 18-JUN-1991 17:06:49.23 >In article <1991Jun17.172930.13518@cunixf.cc.columbia.edu> > es1@cunixb.cc.columbia.edu (Ethan Solomita) writes: > > >Memory is cheap, but Mathematica can use more than 9MB of RAM. Get a > >computer with virtual memory. > > > >-Mike > > And wait for it to page in and out? When memory is > $60/meg? What's the point? So get 18MB if you need that much. The > time it saves you (if you need it) makes it more than worth the > cost. > >The problem is you don't know how much you will need. People run some >pretty large Mathematica jobs.I'm willing to bet there are times >when 32MB of RAM is not enough. Besides, if a job is running for >hours you don't want to find out half way through that it ran out of >memory. Let it page to disk. If you are using the machine for >something else the CPU will be given to another task while the system >is paging. >-Mike OK, I understand, the A3000 is not too bad, especially if you could get a 68040 card for it. I heard there was a german company who has a Virtual Memory Handler for their harddrive. Can it be run on a standard A3000? (without their harddrive?) Is it save? Could Maple make it's own virtual memory handler? That would be a good idea I beleive. BTW I saw a MAC SE/30 with 2 MEGS running system 7 with Virtual Memory. What a joke! The system allocates 1.7 MEGS for itself, leaving 300 K for applications. Starting SUPERPAINT allocates 1.2 MEGS for superpaint and has to swap .9 MEGS to run it. Everytime you switch to the FINDER it swaps again. Good thing it doesn't have real multitasking! Question: Since on a MAC you need to specify the size of an application (in the INFO window) does it still give an out of memory error if it needs more than that size, even with Virtual Memory? (That seems stupid) Do you still need to quit to change that size? (Even more stupid) Does the CPU still spend time on the Memory Manager? besides the MMU ?? Nils Gokemeijer (NJ_GOKEMEIJE@FANDM)