From: pd@doc.ic.ac.uk (Philip Daniels) Subject: Re: Coherent vs. Linux - a comparo Date: 21 Jun 1993 18:57:45 +0100
In article <gahC8z8uz.3vw@netcom.com> gah@netcom.com (Gregg Hungerford) writes:
>pd@doc.ic.ac.uk (Philip Daniels) writes:
>> So if you find paging too slow on a PC use the same solution you used for
>>the MIPS box, add more RAM. Seems pretty obvious to me!
> You missed the point. All I am saying is that people may have false
>expectations of virtual memory on a low end machine. Certainly it's
>better than not having vm, but one must be prepared for a lot of
>thrashing (and thus rebooting).
Its generally not a good idea to reboot your computer if it is thrashing.
Far better to wait for it to stop. But since most Linux machines are likely
to be single user (or 2 or 3 at most) they are unlikely to thrash. Certainly
my machine has never thrashed, I can't run enough processes to make that
happen.
It can run out of vm, but that's a different problem, hopefully to be fixed
soon.
I don't think that people have unreasonable expectations of VM on a PC.
Everybody knows that disks are slower than RAM, don't they, no one expects
it to be any different! You get what you pay for, nobody in this group is
expecting to outperform a workstation costing God knows how much with a $1000
PC and a 150Mb IDE drive.
BTW, just how much did you pay for those 3ms disks (I didn't know such
beasts were available). Is that actual mean access time for head travel or
does it have a disk cache?
>
>> Depends on what you are doing doesn't it? Actually, one could make a very
>>good argument for running Linux on such a system - since it is so small and
>>tight it would make far better use of the available hardware. I know that I
>>could run X very satisfactorily in 32Mb, thanks.
>
> Running EITHER coherent OR linux on a system like that is like
>putting a lawnmower engine in a Cadillac. For the kind of money
>you've put out in ram (about $1000?), it's a bit absurd to cut
>corners on an operating system.
At UK prices, 25 per MB x 32 = 800 British Pounds ($1200). I presume MIPS
simms are more expensive than PC simms, maybe you get a large purchase
discount. Seems about right.
>
>> Hmm, I run on a 14'' Ok and I think there is very little need to go over
>>17'' unless you are doing CAD or development work, where having a lot of
>>screen real estate really helps.
> I prefer the smaller monitors, but I don't like spending my time searching
>for and resizing windows.
Yes, so what IS your point? That you don't have to go looking for windows
on Coherent? I think your point is getting a little garbled here, at least I
know I'm not following you.
BTW, I find MS Windows to be usable on a small monitor because of that
ALT-TAB switching trick, very slick, but that's a completely separate topic...
>
>> BTW, what's a "high end" operating system? One so bloated in can't run X
>>in less than 64Mb of RAM? Sounds like those MIPS people should look into
>>porting Linux :-)
> Again, you are putting a lawnmower engine in a Caddy...
Duh. Smiley on the end, but since you didn't make a reasonable response we
can only assume that my allegation is true, though I find it very difficult to
believe. It's more likely the problem with poor performance on your workstation
was with any large apps you were running, in which case this whole discussion
(Linux vs Coherent vs OSF (?)) is irrelevant, so I don't know why you brought
it up, other than to say "3ms disk is faster than 15ms disk". So tell us
something we didn't already know.
>
>> Type of video system is very important. I run X at more than acceptable
>>speed on my 486SX-25 / S3 combination.
>
> That's not much processing power to be divided up (at least for
>my needs). I'm running coherent on an equivelant system and the
>4 virtual consoles are as much as my system can cope with. I also
>don't find the 486 sx to be a sound investment. Isn't that just
>a 16 bit bus and no co-processor?
No, its a 32 bit bus and no co-pro. It was a sound investment for me at the
time as true DX systems were going for quite a premium over SX systems at that
time in the UK and most general UNIX work (editing, compiling) doesn't use it.
I have a 50Mhz motherboard though, so I can easily boost performance when I
can afford it (I expect chip prices to drop quite a bit in the next 18 months,
which is why I delayed buying one, coupled with a lack of money :-()
I can drop in a 100-Dx3 when they become available.
> In general, you missed that point I was trying to make. I'm sure
>both linux and coherent are fine for low end systems, but if one
>has lots of ram, high speed disk and a fast processor, it's penny-
>wise and pound foolish to try cutting corners on a decent operating
>system.
Sure, but not everybody has or can afford to spend $25,000 on a workstation.
There is also an argument that says that one can afford better hardware if
one has a free OS, this is especially true for a typical population of Linux
users.
You also don;t seem to be able to decide what your point is. Originally you
were having a go at VM on >3ms disks, now you seem to be trying to bash Linux.
Got anyting constructive to say?
Phil "I'm almost ready to vote for a .advocacy group" Daniels.
--- Phil. (pd@doc.ic.ac.uk)
Brain failure (cerebral coretex dumped)