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Re: Linux Server
On Thu, Mar 25, 1999 at 06:45:00PM +0200, Ariel Biener wrote:
> On Thu, 25 Mar 1999, Ury Segal wrote:
>
>
> I have to concurr. These calculations are wrong. For example, using a Dual
> R10000 SGI Origin 200, with 512MB memory, we accomodate 130 users, running
> netscape, matlab, mathematica, and so on. The machine is indeed loaded,
> but works fine.
>
> I don't think more than a dual pII/pIII 450 (or dual Xeon 450, although I
> am not sure it's really needed, price/performance wise), with 512MB and a
> FAST disk, i.e. scsi UW2 >10,000rpm scsi disk is needed.
>
> Since we here have quite a vast experience with multi user servers that
> serve a large community, I think our experience is of value. I bet Doron
> Shikmoni can add what he knows about BIU.
I've just one thing to add - CISC(and thus x86) architecture is far from being
very similar with RISC architecture, and there are a lot of things which have to be
put in mind when choosing platform for server or when bulding server upon existed
hardware . If you're talking about x86 architecture to built a server intended to
serve up to 30 users at a time , you should consider that each user's program
is assigned memory in 4K pages (on other architecture this size is different as you
know) , hence even if he uses 20bytes array he really takes 4K . Any object oriented
program which requires only 20K for its data can naturally take up to 1MB for its
instructions segment , due to the fact that its built in object oriented manner.
Any process in the system handled by kernel has its own descriptor in the process
table and this table also depends on the architecture , not just on the kernel.
For example x86 architecture can hanlde up to 100 processes simultaneously while
Alpha is able to handle 10000 . Some specially built SMP servers can access same
regions in memory at same time , while no-one from Intel does . And so on and so on.
So , as a final note (only my final note , someone can read this and decide something
completely different :) - there are a lot of things to think about them, but to decide
which server best fullfills your needs you've to know exactly what are you going
to do with it . If the goal is to use it as application server while running only
applications like X/Netscape/Emacs/DDD/etc. and not for some heavy applications
like CAM/CAD/3D modeling - this configuration is good enough , if not - you need
something more powerful .
Best wishes,
Mike.