*BSD News Article 6448


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Path: sserve!manuel.anu.edu.au!munnari.oz.au!spool.mu.edu!uunet!mcsun!uknet!edcastle!aiai!richard
From: richard@aiai.ed.ac.uk (Richard Tobin)
Newsgroups: comp.unix.bsd
Subject: Re: 16-colour X server?
Message-ID: <7688@skye.ed.ac.uk>
Date: 13 Oct 92 15:40:03 GMT
References: <7656@skye.ed.ac.uk> <1992Oct13.015735.7298@ntuix.ntu.ac.sg>
Sender: news@aiai.ed.ac.uk
Organization: HCRC, University of Edinburgh
Lines: 24

In article <1992Oct13.015735.7298@ntuix.ntu.ac.sg> eoahmad@ntuix.ntu.ac.sg (Othman Ahmad) writes:
>I used to think that 8-bit is too much but when I run the XFree86, it
>is so fast that there is no need to speed it up by 2 time. I'm only using
>a non cached 386 25 Mhz without 387.

The presence of a 387 will make no difference.  The speed of the processor
isn't very important since the limiting factor is the bandwidth of the
stupid PC bus.  On a machine with a local bus to the video card performance
is fine, but with a vanilla SVGA on the ISA bus it's pretty poor.

>In fact 16-bit is the ultimate. There is no need to go any futher.
>The 24-bit and 32-bit DACs are wasteful because they do not take into account
>human visual perception.

Regardless of human perception, there's an advantage in the simplicity
of allocating 8 bits each to red, green and blue.  And such a 24-bit
system doesn't need a 24-bit *DAC* - it has separate 8-bit ones for each
colour.

-- Richard
-- 
Richard Tobin,
Human Communication Research Centre,                       R.Tobin@ed.ac.uk
Edinburgh University.