[AG-TECH] Display machine on Linux

[Andrew Howard]

We're running the AARNet room grid node and our
portable/development node on FreeBSD.

Both the room based display system and the portable system/
development have an AGP Nvidia GeForce 4 Ti 4600 card. The
room display system has an additional three Geforce 4 MX 420
PCI cards supporting a five screen virtual display with two
of the five screens accelerated.

Due to the PCI slot limit (3 * 32bit PCI,  2 * 64bit PCI)
in the Dell 530 systems we use, we're running two nodes for
video capture with Brooktree 878 cards and the final system
for audio with a Soundblaster Live card. The portable
system uses a laptop for audio and combines the display and
capture functions into a single system.

Like the vislab node the systems synchronise on room change.

We hacked together some perl and shell scripts which
execute via ssh and then found Chris's vvd code about an
hour later.... it handles things in a much cleaner manner
and we'll probably replace the current code with vvd
at some time.

OS config on all of the systems is "off the CD" FreeBSD 4.7
cvs updated for bug fixes.  The kernel is tuned for the SMP
hardware.

The applications (vic, rat, vnc, tkMOO) were initially
installed from the ports collection

http://www.freebsd.org/ports/mbone.html

We've been moving to the openmash versions of vic and rat
over the past few weeks starting with the display node. The
additional layout functions like scrollbars make displaying
large rooms like the venues lobby much easier.

We're using the initial public beta version of the Nvidia
FreeBSD X drivers which support Twinview and OpenGL
acceleration on the Ti 4600. The performance is outstanding
but we're still tracking down some stability problems under
heavy I/O load on the room display system which doesn't occur
on the development system with two Nvidia cards or when using
the standard XFree86 nv drivers. The support we've had from
Nvidia for an unsupported beta driver is outstanding so we're
willing to work through the initial problems.


-- 
Andrew Howard                       | AARNet Pty Ltd
Phone:  +61 2 6276 6904             | Australian
Mobile:    04 2200 7249             | Academic and Research
Email:  Andrew.Howard at aarnet.edu.au | Network