Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!snorkelwacker!bloom-beacon!lupine.UUCP!klein From: klein@lupine.UUCP Newsgroups: comp.windows.x Subject: Re: X terminal question Message-ID: <8911170408.AA06476@ramona.ncd.com> Date: 17 Nov 89 04:08:14 GMT References: <7003@pt.cs.cmu.edu> Sender: daemon@bloom-beacon.MIT.EDU Organization: The Internet Lines: 61 (Disclaimer - Since I work for NCD, I obviously am not unbiased towards NCD displays, but since I use a configuration every day very similar to what you describe, I think I can add some useful insight :-) I am considering adding 3 X terminal, probably from NCD, to a DECstation 3100 with 8meg of RAM. I am wondering how good of an idea this is. I would like general comments in addition to answers to some specific questions. 1) What kind of resources will the X terminal use on the DECstation? Specifically, will it need disk space(how much), RAM, and CPU? The only disc space required by an NCD above and beyond that used by a normal user is < 10 mbytes for boot images, fonts, and configuration information. Trivial, really, compared to what 'user files' would most likely take, or /usr/bin. CPU usage is *very* application dependant. A good developer can bring *any* computer to its knees - how many 'make's can you type in 60 seconds? In our particular environment, though, we have *plenty* of cpu power to keep 8-12 users going. (We use the machine for general 'office automation' use; i.e, word processing, mail, occasional compilation, etc.) We have found, however, that X users tend to be much happier when the host has *plenty* of RAM, though. In our environment, we run 16 mbytes of RAM and are happy, but if I added any more users to this system, I would bump it to 24 mbytes. For an additional 3 users to a DECstation you should be able to get away with 8 mbytes of RAM, but after playing with this system and a good variety of other of the current 'hot' UNIX hosts, I wouldn't even consider trying to run UNIX (I don't care whose) on anything less than 16 mbytes. Bottom line on RAM - trust me, buy more! 2) How much of a CPU burden is an X terminal? I would make the argument that the 'CPU burden' of an X terminal is noise when compared to the overhead of multiple users running multiple applications. I wouldn't be so concerned about 'X overhead' (whatever that might be), but I would think seriously about what applications the user's will be running. Are they all running 8 hour finite element analyses? Are they simply logging in once and a while to read their mail? We have one programmer that can bring our Sun 4 *completely* to a standstill, but at the same time I can run 20-30 users on a lowly microVAX 3500, all very happily reading their mail! It ain't X causing the problem! 3) How do you login to/through the X terminal? Do you have a login screen or do you have to "telnet" to the DECstation? There are a variety of ways to get started with X terminals. Most support a separate 'telnet' session that allows you a way to initially connect to the host and kick off some X applications. Most will be work with an MIT supplied client called 'xdm', (the "X Display Manager"), some more elegantly than others. 4) Are there any specific aspect of the DECstation that might effect the instalation/performance/functionality of the X terminal? The only specific aspect of a DECstation that I know of would be DECwindows itself. There are some finer points in making this work that you might want to know about. If this is of interest to you, let me know, otherwise I'll leave this for another discussion, some other time.