bob@imspw6.UUCP (Bob Burch) (12/23/88)
From Ted Holden, HTE: ........................... From: John Hardin, HP Information Networks, Cupertino, CA >> ... the idea of allowing DEC, HP, Perkin Elmer, >>IBM etc. to each continue selling their own little proprietary OSs for minis >>is simply no longer acceptable to the US government as of right now, and will >>obviously not be acceptable to most corporations either. >> >>Ted Holden >>---------- >I'd like to reply to this, but first let me make it clear that although I >work for HP, I am not representing them here and any opinions I post here >are my own. Now that that's out of the way... >Obviously your addition of the word "little" above shows a disdain of the >other operating systems you mention. 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. Perhaps it's the granualarity of locks >available or the extra disk accesses to support the multi-level directory >structure. Often this extra overhead is more cost for more features, but >these extra features are usually of most use to software developers, not >the accounting department in a commerial environment. Hopefully, we are >entering an age when the efficient use of the human is of more importance >than the efficient use of the machine, but in the meantime Unix may not >be the best answer for everyone. There is a simple and deadly counter-argument to any and all of this and, again, you don't need to be Albert Einstein to figure it out: At any point in time, you will buy yourself some gain in performance going with a proprietary OS versus UNIX for a given piece of hardware which, presumably, wasn't specifically built to run UNIX (something like one of the Gould "firebreathers" which WAS specifically blueprinted for UNIX is a different story). I don't know exactly what the performance gain is for a typical VAX or HP mini but, for the sake of argument, let's assume it is 50 percent, which I suspect is being generous. So you and I each buy one such computer at the same time, mine with UNIX, yours with the proprietary OS, and you've got me by 50%. In less than two years guaranteed, and in probably less than one year, there will be somebody out there selling a machine which is 300% faster and stronger and sells for 1/3 the price we paid. No problem for me; I just go out and buy one and, one week later, I'm back rolling, 250% faster than you can roll, and all you can do is think, wistfully, "Gee, if I only hadn't bought this ____ed-up lemon with this non-portable operating system........." Ted Holden HTE
davidsen@steinmetz.ge.com (William E. Davidsen Jr) (01/05/89)
In article <209@imspw6.UUCP> bob@imspw6.UUCP (Bob Burch) writes: | There is a simple and deadly counter-argument to any and all of this and, | again, you don't need to be Albert Einstein to figure it out: | | At any point in time, you will buy yourself some gain in performance | going with a proprietary OS versus UNIX for a given piece of hardware | which, presumably, wasn't specifically built to run UNIX (something like | one of the Gould "firebreathers" which WAS specifically blueprinted for | UNIX is a different story). I don't know exactly what the performance | gain is for a typical VAX or HP mini but, for the sake of argument, let's | assume it is 50 percent, which I suspect is being generous. So you and I | each buy one such computer at the same time, mine with UNIX, yours with | the proprietary OS, and you've got me by 50%. Unfortunately, at least on a VAX, your argument does not seem to match the observed results. I talked to four system managers who handle both VMS and UNIX VAXen, and even those who really dislike UNIX as an interface agree that UNIX will run 20-30% more users on a VAX, at least when doing typical things like edit, compile, read mail, light computation, etc. The reason is that VMS has a lot of overhead in starting a process, and a lot in file i/o, due to the many types of file. You have some features added in VMS (which may or may not be needed), but you pay for them. I will agree with you that it is possible to write an o/s for any given computer which will maximize performance, but it is not a given that performance is the goal of a proprietary o/s. In fact, given the low overhead of process startup and file i/o in UNIX, there is usually a limited place for improvement there. Using the fast file system (BSD and V.4) the overhead of directory access in UNIX is low. The vendors want to have features which (a) the user can understand, and (b) which lock the user into the o/s. If UNIX has an overhead of 30% (pick any small number), the most a vendor could gain would be that overhead, even with a perfect o/s. In practice most applications don't have even that much overhead, but that's VERY application dependent. This doesn't mean that UNIX is perfect for every application and machine, but it suggests that a vendor will add features rather than performance to make his product appeal to users (or actually management, which isn't the same thing at all). To repeat a few of your lines: | At any point in time, you will buy yourself some gain in performance | going with a proprietary OS versus UNIX for a given piece of hardware | ... The assumption that proprietary=faster is not universally true, although I agree that for any machine there is room to custom tailor the software to the hardware. Perhaps the decision of Cray and DEC to go with UNIX for new machines indicates that portability is important also, and that custom tailored systems are often so expensive to port to new architecture that it is impractical. It could be argued that this may actually slow the development of new hardware, but I have nothing to back that other than gut feeling. -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me
aglew@mcdurb.Urbana.Gould.COM (01/14/89)
>(something like one of the Gould "firebreathers" which WAS specifically >blueprinted for UNIX is a different story). If by Gould Firebreather you mean a Gould Powernode, well, it wasn't *exactly* designed to run UNIX. Basically, the Powernodes are a virtual memory version of the Gould Concept line; the Concept line was the preeminent real-time flight-simulator machine of its day (in fact, in many ways it still is), and typically ran a proprietary operating system called MPX. The Concept line was basically your brute force fast iron approach: simple instruction set, simple interrupt structure, fast I/O. It shouldn't be too surprising that simple and fast runs UNIX as well as a proprietary OS. However, the virtual memory and base register extensions of the Powernode series were pretty much UNIX oriented. The Gould NPL line of processors was originally designed to run a proprietary rewrite of MPX, but the rewrite turned out to be too expensive, so the NPL can be said to be more UNIX oriented than most.