Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!cs.umn.edu!msi.umn.edu!noc.MR.NET!gacvx2.gac.edu!gacvx2.gac.edu!scott From: scott@mcs-server.gac.edu (Scott Hess) Newsgroups: comp.sys.next Subject: Re: Memory Message-ID: Date: 15 Jun 91 06:11:46 GMT Article-I.D.: mcs-serv.SCOTT.91Jun15011146 References: <1991Jun14.125927.18256@neon.Stanford.EDU> Organization: Gustavus Adolphus College Lines: 121 Nntp-Posting-Host: mcs-server.gac.edu In-reply-to: zimmer@calvin.stanford.edu's message of 14 Jun 91 12:59:27 GMTLines: 121 In article <1991Jun14.125927.18256@neon.Stanford.EDU> zimmer@calvin.stanford.edu (Andrew Zimmerman) writes: In article scott@mcs-server.gac.edu (Scott Hess) writes: > >[ Lastly, some flamage. Alot of people make fun of EPS (and > lately, myself) for our insistance that no matter the > raw performance of your CPU, you really are going to need > the memory and disk space. Rather than attempt to argue, > as most apparently don't listen, I would advise anyone > who's doubtful to go out and find a NextStation400M > w/16M or 32M of memory, and a 105M machine with 8M, and > do a side-by-side comparison. It will literally blow your > socks off. We're not talking fractions of a second > differences here - in many cases, it's order of _magnitude_. > For instance, launch Edit on a file on the 105/8 machine. > Then, on the 400/16 machine. The 400/16 is fast enough > that you really don't notice the launch time, while the 105/8 > takes long enough that you start to get up to pace the room. > That's the difference between enjoying your time on the machine, > and spending it in frustration . . .] I would be interested in getting some hard numbers on how much faster a 16 meg machine is compared to an 8 meg machine. Opinions that I have heard range from "worlds of difference" to "doesn't help at all". That's tough. The problem is that the machine is actually not really much "faster". For instance, it won't calculate a small picture of a Mandelbrot set any faster. Anything that can fit in memory will run about the same speed with the extra memory. What really is noticeable is the launch speed of apps and the like. When I lauch Edit on a file on a 105/8 machine on a network, the disk goes crazy - swapping, I assume. At the very least, launching the same way on a 105/16 machine does not have nearly the disk activity. The time difference is something like 16-20s to 3-5s, which is respectable. That's on a network file, not a local file (shave maybe a second or two, then :-). Of course, once you're editing a document, it makes no difference. But, many people, I've found, don't spend all their time in a single document of a single app. Well, I don't, and most people I work with don't. Then again, these are mostly developers and sysadmins, so they don't spend much time in a single window, but jump between them alot. That's where the memory really makes a difference. We have noticed that a 200/8 network machine tends to do a lot more swapping to disk, and the Launch time is greater. This machine was just upgraded to a 200/16 (with parity). The owner commented that he did not see that great of speed improvement. One thing we noticed here (Well, actually, Gustavus is "here", even though I'm not there at this time) is that when the netboot clients (accelerator disk+8M memory) were upgraded from '030 to '040, there was no noticeable speed increase. When either the '030 or the '040 was upgraded to 12M or 16M, there was a noticeable increase. Launch time should mostly be a function of the hard disk speed (or network) and the amount of memory that is being used for data. The text (instruction) memory should not be paged back to disk. Relaunching a hidden App would of course be faster if it had not been swapped out to memory. Do the people who notice a big speed increase tend to run many Apps at the same time? When you say "Launch", are you talking about the first launch, or launching from a hidden state? Well, hard disk speed makes a difference, but I think memory makes more. For instance, I run IB, Stuart, Workspace, Edit, TimeMon, IconBounce, and Background constantly. The last three don't really count, as they'll quickly achieve a small working set of pages, as I don't touch them after they launch. IB is a large app. The main thing is that it doesn't use the shared libraries, for the most part. So, it looses alot of memory to that. Stuart's small, as is Edit, but Workspace is relatively large, also. And Edit can be large, if you're editing lots of files. Most of my switching is from Edit to Stuart, with Workspace being a distant third, and IB way back there. You can notice the difference between 8M and 16M even when switching between Edit and Stuart, but it's not too bad. You can really notice when switching to a Workspace you've not touched in a couple minutes (when you've been editing/compiling, etc). And you _really_ notice when you call up IB, or any other app that's sat in the background for awhile (like 20 or 30 minutes). On the 16M system, there really isn't a whole lot of difference when switching between any of the apps I list, unless you've let them run for a long time. On an 8M system, you really can tell. I'll give a short list of some launch times for a couple apps on the NeXT. These are not hard& fast measurements. It's a relatively unloaded system, and I'm basically estimating the times. The hardware is a stock NextStation400/16, with nothing else (except the modem I'm talking to you through): Edit: 1.5s Edit on /etc/termcap: <3s IB: 3s Librarian: 4s Mail: <3s Preferences: 5s Preview: <2s WriteNow: 3s Stuart: 3s Improv: 4s Diagram: 5s IconBounce: 1.5s WordPerfect: 7s SoftPC: 4s Alas, I've not got Mathematica on my system, so can't really test it. Later, -- scott hess scott@gac.edu Independent NeXT Developer Graduated GAC Undergrad! Note: I have moved home for a time. My email address will still be valid. Any SnailMail should be redirected, along with phone calls. At the least, my parents can tell you how to get hold of me, or forward any mail . . . Old: PO 829, GAC, St. Peter, MN 56082 (507) 933-8466 New: RR#4 Box 227 Pipestone, MN 56164 (507) 825-2788