Re: 28.8K modem, pppd and Multiface III card

[Ignatios Souvatzis <ignatios%cs.uni-bonn.de@localhost>]

   Date: Wed, 21 Aug 1996 15:27:09 -0400 (EDT)
>    From: Bruce Drake <bruce%synxcti.com@localhost>
> 
>    On Wed, 21 Aug 1996, The Terminator rAT wrote:
> 
>    > Bruce Drake writes:
>    >  > Are there any other experiences out there?  I wouldn't mind hearing 
> from
>    >  > you myself.
>    > 
>    > Here's a weird (well, maybe not so weird...) effect of PPP/A3000 
> serial...
>    > 
>      snip snip

>     If
>    you add the fact that Xdaniver uses as much of the display width as
>    possible, the chip memory's bandwidth is just about used up, and other
>    devices like the internal serial port will suffer as a result.  This is
>    where using another video display card is a win in overall machine
>    performance, even if you have to use the CPU to do all the graphics (and
>    not the blitter). 
> 
This is the problem.

You should get much better results with Xdaniver -depth 3 (or smaller).

(although most stupid programs dont know how to talk to a depth 3
server, so you'll want depth 1 instead (b/w display)).

-depth 3 gives me the feeling of half a magnitude more X11 performance
than -depth 4.
 
Then you'll need LEV6_DEFER for faster response to the serial input
interupts, and in case you don't have it, a -current system (or -1.2)
instead of -1.1 or older ... one related serial driver bug was fixed
by me some time ago.

Actually, you'll still need more RAM for a decent performance, but it
shouldn't be that bad anymore.

Oh yes, for even more performance, kill the modem's compression, and
use the bsdcomp option to pppd on both sides of the link. A few cpu
cycles to do compression (at the software interupt priority) is much
cheaper for the overall performance than a doubled interupt rate.

Regards,
        Ignatios Souvatzis