CG3 + gp1, how to configure for best X11R4 performance?

[dd at mips.com]

In article <873 at brchh104.bnr.ca> bmh at tigger.cs.unc.edu (Brad Hemminger) writes:
>We have been given a Sun 4/370 workstation, configured with a Sun cg9 card
>and a graphics processor gp1 (?).  We are attempting to run some of our
>X11R4 applications on it.  After some initial testing we decided that the
>x11 under the cg9 would not fit our applications (24 bits as too slow),
>and we have managed to obtain the loan of a cg3 (to the best of my
>knowledge :-) framebuffer card.  We have installed the cg3 and it works,
>however, I'm not sure that we're getting the best performance possible
>with this combination.

X11R4 does not have any special support for the GP2 or CG2/CG3/CG5.  It
completely ignores the GP, and treats the color board as a dumb frame
buffer.

Sun OWV2 does not use the GP, but can coexist with it.  It takes some
advantage of the color board hardware.

>If anyone could help us out with in regards to how
>best to configure these cards (i.e. should we even have the gp in, why
>does the cg3 show up as a cg2 at boot time, are there switches we can set
>on the cg3 to tell it what/how to emulate, etc).

There's no advantage to having the GP in unless you are going to run GPCI
applications.

The CG3 shows up as a "cgtwo" because the cgtwo driver supports the CG2,
CG3, and CG5 color boards.  The driver properly identifies the board as a
"Sun-3 Color Board".

There are no switches you need to set on the CG3.

>Our main speed concern
>is updating large images (ZPixmaps) in X11R4.

Updating large images is transport bound.  You should use MIT-SHM of
course, then it will probably be VME bus bound.

David DiGiacomo, MIPS Computer Systems, Sunnyvale, CA  dd at mips.com