X costs (was X sucks)

[Joshua Osborne]

In article <1991Apr12.192658.25172 at ico.isc.com>, rcd at ico.isc.com (Dick Dunn) writes:
> gamiddle at watmath.waterloo.edu (Guy Middleton) writes:
> > X does suck, but its popularity seems inevitable, since it doesn't cost any
> > money...
> 
> Guy, I know what you mean, but you're wrong.  X costs a bundle.
> 
> First, it costs at least 4 Mb extra RAM, one notch of CPU upgrade (and an
> FPU helps), and probably about 20 Mb of disk--PER MACHINE.  There are some
> additional display costs (relative to what a better window system would
> require), but they're harder to figure.

I run 22 VS2000's off of about 15Megs.  Total.  Including the one 6M read-only
swap.  Adding more VS2000's costs about 40 bytes each.

Sure the VS2000's are only X terminals, sure they are (moderately) slow ones
at that (Sun 3/50's are fast enough).  But the people who use these things
are used to Sun 3/60 speeds, and we won't (ever) see that on a VS2000.

> Next, although the software base code is "free", it takes a lot of work to
> make it into usable software.  You have to port the server to various
> display interfaces 

Normally you get a server that already works.  Still it is far easier to port
something you have source to then something you don't.

>                     (and in the PC-compatible world, there are scores of
> them); then you've got to tune it up.  Both of these are made much harder
> by the gratuitous complexity in X.

Much of the "gratuitous complexity" is to make X easy to port.  Just look at
the Visual types and think about it, they expose the user level code to the
reality that you server only has 128 colors rather then making the server cope
with a client that thinks it can ask for 600...    It also deals with direct
map vs. color table lookup, etc.

You want to port the X server to a new framebuffer?  If you want it slow,
you can write 10 (easy) functions, all in one directory, 3 different .c files.  Want it acceptably fast?  Write about 25 functions (I haven't done this, I have done a 10 function port).  Want it fast?  Work on it for awhile.

> -- 
> Dick Dunn     rcd at ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
>    ...While you were reading this, Motif grew by another kilobyte.
                                     ^^^^^
Not over here, we erased it.
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