Re: Graphicspeed with X under NetBSD

["Eduardo E. Horvath" <eeh%one-o.com@localhost>]

On Thu, 16 Jan 1997, Neil Brendan Clark <Neil Brendan Clark wrote:

> 
> In message <Pine.NEB.3.95.970116155819.25914B-100000@smaug>, Alexander Sorg wr
> ites:
> >The current X-server takes advantage of the aga-chipset. You can open
> >displays with a depth from 1 to 8 bits. But at 8 bits it becomes really
> >slow. It's the same effect as under Amiga-OS, the chips are simply too
> >slow. The graphic-speed when using a screen with a higher depth reduces
> >as it does under Amiga-OS. When using a depht of 3 Bitplanes it seems to
> >be a little bit slower than the Amiga-OS. I think the X-server is not so
> >efficient as Amiga-Intuition.
> 
> Indeed. I had a few nightmares getting it going efficiently (a 1bit screen
> is not ideal, a 4bit screen does not have enough colours, and some
> programs do not like 5bit screens) until I started using the X server
> in 4bit greyscale mode, i.e. my .xserverrc looks like this;
> 
> exec X -width 700 -height 535 -depth 4 -X 4 -Y -10 -emulatemiddle -cc 
> GreyScale 
> 
> This way all programs get the "colours" they need as all 16 grey shades
> are fixed at startup. Not as good as proper colour, but better than
> monochrome. YMMV.

As far as I know, the ecs/aga X servers do not make use of the blitter, so
thew will run slower than Intuition.  Also, remember that the X server is
a user process and parts of it may be swapped out, and it must communicate
with the clients through a socket and you will see a big performance
difference.

As for the blitter, to take any advantage of it a kernel driver must be
written so it can be serviced by an interrupt handler instead of being
polled.  Otherwise you may see a performance degradation over CPU
blitting.  Then the X server must be modified to use the bitter driver. 

I wrote a blitter driver several years ago, but it was never integrated
into the sources and now my machine is no longer functional.

=========================================================================
Eduardo Horvath                         eeh%btr.com@localhost
"Cliffs are for climbing.  That's why God invented grappling hooks."
                                        - Benton Frasier