dhesi@bsu-cs.UUCP (Rahul Dhesi) (12/20/88)
(Moving this from comp.sys.ibm.pc to comp.unix.questions.) In article <4330119@hpindda.HP.COM> hardin@hpindda.HP.COM (John Hardin) writes: >While I agree with your prediction of >the role of Unix in the next few years, I can also see why there continue >to be propietary OSs. One reason is the inefficiencies of Unix. I am no >Unix kernel expert, so I don't pretend to know why, but I have seen that >a propietary OS can support many more time-sharing users than Unix when >both are run on the same hardware. Counterarguments are possible. For example: o Proprietary OSs often support more users than UNIX by restricting what these users can do. For example, they may not allow job control (only one active job) or make it inconvenient; they may not allow pipes (got to go via disk files, slowing things down, so it seems like more people are doing work but each person is getting less done); they may not have many of the UNIX utilities like mail, wc, grep, awk, etc., so you just don't do those things at all o Proprietary OSs probably don't have Usenet software, which may mean a lighter load on the machine. So you read news from your home machine, and post an article saying that the proprietary OS at work is more efficient :-) o Proprietary OSs may require a special terminal with local intelligence (e.g., IBM) thus offloading much work to a $2,000 terminal, rather than letting you use a $500 terminal for the same purpose. Thus, to support 100 active users, you might need an additional investment of $2000 * 100 = $200,000 (in addition to the cost of the central machine). The proprietary OS may appear more efficient if you only looked at the cost of the central machine and forgot about coaxial cables, front-ends, terminal multiplexors, intelligent terminals, and other paraphernalia that the proprietary OS may *require* rather than just *allow* o UNIX is less efficient than many proprietary OSs because it is written mostly in C. An individual vendor is welcome to rewrite more of the kernel and utilities in his own proprietary machine-dependent language and speed up UNIX, or a proprietary UNIX clone in such a machine-dependent language, without sacrificing compatibility with UNIX applications o It is possible to have a proprietary OS emulate most of the UNIX system calls, allowing both efficiency and portability o Hardware is cheap enough that the additional hardware cost to make a UNIX-based system as efficient as one with a proprietary OS is probably smaller than the additional cost in software and inconvenience of using a proprietary OS By the way, UNIX itself is a proprietary OS. Perhaps we should be talking about "portable" and "unportable" operating systems. -- Rahul Dhesi UUCP: <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi
hardin@hpindda.HP.COM (John Hardin) (12/23/88)
In response to a posting of mine defending the current existence of proprietary OSs on efficiency grounds, Rahul writes: >Counterarguments are possible. For example: > >o Proprietary OSs often support more users than UNIX by restricting > what these users can do. For example, they may not allow job > control (only one active job) or make it inconvenient; they may > not allow pipes (got to go via disk files, slowing things down, > so it seems like more people are doing work but each person > is getting less done); they may not have many of the UNIX > utilities like mail, wc, grep, awk, etc., so you just don't > do those things at all Capabilities like pipes, grep, awk, etc. are of great use to developers (like myself) but often not to commercial users who spend almost all of their time in some transaction processing program. They may rarely, if ever, talk directly to the OS. >o Proprietary OSs probably don't have Usenet software ... The comparison I was making was between a proprietary OS and a Unix system NOT running Usenet software. I agree that the comparison would not be fare if Usenet load were added only to the Unix system. >o Proprietary OSs may require a special terminal with > local intelligence ... This also would not be a fair comparison so the OS I was comparing to Unix did not have this requirement. >o UNIX is less efficient than many proprietary OSs because it is > written mostly in C. ... C is a pretty efficient language. I would be suprised if this were the reason for the difference. I suspect, instead, the extra disk accesses needed to access files in a multi-level directory structure and the course granualarity of locks in the kernel that keep processes waiting that should be able to continue processing. >o It is possible to have a proprietary OS emulate most of the > UNIX system calls, allowing both efficiency and portability Very true. Unix is certainly not the only possible portable OS. >o Hardware is cheap enough that the additional hardware cost to make a > UNIX-based system as efficient as one with a proprietary OS is > probably smaller than the additional cost in software and > inconvenience of using a proprietary OS You can make a system faster by adding such hardware but note likely more efficient. Faster disks, CPUs, memories, etc. can all be used to benefit the more efficient proprietary OS as well. Though I agree that Unix is the best OS available today for the kind of work engineers and software developers do, I can still see reasons for commercial users with certain needs to be less impressed. Hopefully, Unix will continue to improve and other criteria will entice the commercial user toward Unix so we can all benefit from a common OS base. Again, the comments I made here are my own opinions and do not represent my employer. John Hardin hardin%hpindda@hplabs.hp.com -----------------------------