How to choose a new 386 UNIX PC...
scottw at ico.ISC.COM
Fri Sep 22 02:48:35 AEST 1989
>From article <648 at visdc.UUCP>, by jiii at visdc.UUCP (John E Van Deusen III):
> If the software is
> MSDOS-based then it is hard to access the megabytes of memory needed to
> store the "underlying" areas of the screen.
I'm going to go out on a limb here and say you don't really want
backing-store/saveunder on a VGA based X system. Actually, it's
reasonable to some extent, but you're limited by how much off screen
video memory you've got, which isn't much on Super-VGA. Going back
to system memory for these things is very very slow. You can do
simple stuff (text, lines, polygons) much much faster than you can
do memory to screen and screen to memory BITBLT. The main problem is
for BITBLT, you have to access each pixel 4 times to read or write it,
while for something like text, you can take advantage of some of the
special capabilities of EGA/VGA and go much faster.
> In the latter case, costs really get out of hand because of all the
> licensed software that is required and not really used. I would like to
> suggest that you people at Interactive (or SCO or Bell/Intel) put
> together a stand-alone X terminal software package to run on low-end
> 386s. You have all the software, including drivers, sitting there; it's
> simply a matter of bundling it and putting it on the price list. The
> package could easily sell for $500 a pop; since it would solve the
> problem of poor X server performance on 386 machines running UNIX, and
> there is nothing like it yet on the market.
While we do basically have all the software "sitting there", it's not
quite as simple as bundling it, unless you mean we should supply a
Unix environment with only the X server and no other commands such as
the development system, VP/ix, "ls", "cp", etc. That's an interesting
idea, but is something I'll leave to our marketing people.
What you really want is fast VGA, which is difficult. There are certainly
some boards on the market that are faster than others, and there are new
ones in the works at many companies that are faster still.
> poor X server performance on 386 machines running UNIX,
I'd be interested in which companies' X servers you've seen, and in what
ways you think the performance is poor. Certainly BITBLT is slow, and
it always will be on something like the VGA. Other areas, especially
text performance, are fairly good. It all depends on what you're doing.
If EGA/VGA were great at everything, we wouldn't need things like 8514,
34010, etc. I don't believe that we're suffering too much by running
Unix here as opposed to running standalone.
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