Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!rutgers!usc!sdd.hp.com!mips!twg.com!david From: david@twg.com (David S. Herron) Newsgroups: comp.sys.amiga.advocacy Subject: Re: A3000UX - Born to run UNIX SVR4 Message-ID: <8651@gollum.twg.com> Date: 16 Feb 91 21:33:17 GMT References: <1512@pdxgate.UUCP> <1991Feb9.032953.14709@mintaka.lcs.mit.edu> <1519@pdxgate.UUCP> Organization: The Wollongong Group, Palo Alto, CA Lines: 109 In article <1519@pdxgate.UUCP> hal@eecs.UUCP (Aaron Harsh) writes: >In article <1991Feb9.032953.14709@mintaka.lcs.mit.edu> rjc@geech.ai.mit.edu (Ray Cromwell) writes: >> What makes you think an 040 NeXT will be competitive with an 040 Amiga >>when the inferior NeXT with inferior color and expansion capabilities >>cost the same? > > The NeXTstation has no color and no expansion [slots] available. But >looking through Amiga World (yeah so what if I read it, Amigas still suck :-) >all the expansion cards I see fall into three categories: > 1) RAM/Hard drive cards > Who cares about this? The Station is expandable to 32 Megs, and has > a SCSI connector on the back. The RAM & disk controllers make as much sense for an A3000 as for a NeXTstation. The A3000 can have ~18Megs of memory on motherboard, and has an SCSI-II interface on motherboard. 18 megs is smaller, yes, but is far more than sufficient for both AmigaDOS and Unix use. 32 Megs would be overkill, even (I expect) on a NeXT. What's the kind of SCSI on the NeXTstation? Hopefully it's a "II" ... they're a lot faster (5 megs/sec max rather than 1-1.5 megs/sec max, with the right drive). > 2) Video things (genlocks, Toaster, etc.) .. > 3) IBM/Mac emulators .. There's other things advertised there too ... ethernet, modems, FAX modems, CPU upgrades, CDROM drives, read-write optical disks, software, etc. Ergo.. there's more that you can do with the A3000 expansion capability than what you mentioned. >> Reworded, it sounds the same. The slab is virtually useless. The $3200 >>model is almost unusable. An A3000 with an 040 running AmigaDOS wil >>burn rubber for speed. The NeXT is bogged down with UNIX's overhead and >>Display Postscript. Even the A3000UX with an 040 will probably beat the >>040 NeXT because it doesn't waste so much CPU on the interface. > > As CPU speed increases and display overhead stays the same, amount of >time spent on display aproaches 0. Yes, but ... comparing OS architectures says that AmigaDOS will get more out of any CPU than any Unix-y system. That is .. in both Unix and Mach the user process scribbling on the screen is isolated in its own virtual address space away from the virtual address space where the screen hardware is location. Ergo, any data to be scribbled onto the screen has to be _copied_ between (at least) two address spaces. This, all by itself, is quite a CPU drain. I don't know for sure that using Display Postscript (DP) is, by itself, a humongous CPU drain as Ray suggests. There may well be a performance win by making the window "smart" .. that is, if the window is able to handle much of the job of interacting with the user without having to make round trips to the driving process that overhead of doing context switches to make a button change shape when its clicked upon kinda disappears. The worst part of using DP is that the programmers probably will have to program in Postscript. Yes it's possible to program in Postscript, but its "harder" because it's RPN and we're all taught to do our math in INFIX. > Maybe an '040 3000UX will beat a NeXT, but I doubt it. It will do better >at video, but not at number crunching. Someone posted some benchmarks >comparing A3000 and NeXTCube (030 model) a while ago.(I think that was >in the pre-advocacy days). The NeXT was a little faster than the Amiga. Small differences in speed are just that: small. Big deal if the NeXT is 10% faster at number crunching... And besides the lower overhead in making system calls & IPC (because on AmigaDOS all the processes are in the same address space) may well make up for any raw CPU disadvantage. My decision to get an A3000 with Unix (ASAP) is because -- I want to run & work with X. NeXT's dont' use X as their native windowing system so all those gee-whizzy interface building things are useless to me. -- As much as I'd like to get experience with Mach, it is much more important to get experience with SysVr4. After all, the project I'm working on here will be ported to SysVr4 sometime Real Soon Now. -- The system should be a whole lot faster than any PC-clone because of the faster bus & disk interface. > Try doing raytracing in any reasonable amount of time on an Amiga. Try >designing a functional graphical interface to one of your programs in a >half hour on an Amiga. Most of us are not programmers. There are many other interface building programs available besides the one on the NeXT. Writing the user interface is only a small part of getting the program running. There's all that code that sits behind the front end and reads/writes files or whatever.. -- <- David Herron, an MMDF & WIN/MHS guy, <- Formerly: David Herron -- NonResident E-Mail Hack <- <- MS-DOS ... The ultimate computer virus.