VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed Feb 05 2003 - 12:40:35 CST

Dear Jill,
  Unfortunately stereoscopic display is still an area where PC cards and
their drivers fall woefully short of the more costly Unix workstation boxes
from Sun and SGI. I do have a number of comments based on my experiences
with PC video boards and I expect that a few VMD users on VMD-L may have
some comments to add on this subject as well.

As per recent discussions with the NVidia folks, there definitely are
problems with the Quadro cards. The main problem with them is how the
drivers interact with applications that want to use stereoscopic display
modes. According to what I've heard from several users, from other developers,
and from NVidia themselves, the current display drivers they are shipping
drop back to software rendering when an application requests a stereo-capable
display mode, but proceeds to rendering monoscopically. The only workaround
at present is to set VMD, O, and other affected software to force the use
of stereo all the time, but set the eye separation to 0.0. This workaround
still represents a 50% speed loss compared to what should be possible with
the hardware if the problems were solved with their drivers. So far I
haven't heard back from the NVidia people on whether they plan to fix
the problem or not.

Until the stereo problems are fixed, I can't recommend the Quadro cards
unless you plan to run it in stereo 100% of the time and are willing to
live with the eye separation workaround the rest of the time.
One VMD user says that they've had problems getting stereo displays to
stay synced with the Quadro cards. I don't know if their problem is
caused by the Quadro, by their shutter glasses, or by their emitters,
but this is something to be aware of. I'd suggest buying whatever
card(s) you choose from a vendor that will take returns, since these
problems are known to be outstanding issues even with the most recent
Quadro boards.

I don't have any comments on the 3DLabs cards yet, as we don't have any
presently, though we have plans to acquire some for testing in the next
several months. Some of them do require "approved" motherboards, but
I believe the newest generation of cards will work in a standard AGP
slot. I don't recomment the Oxygen line of cards as I've had various
bug reports on those from a number of VMD users. I've heard good things
about the Wildcat series cards however. I'd recommend having a look at
their Wildcat 4 and Wildcat VP cards, some of them do work in standard
AGP slots.

Many users have reported that VMD runs very well on the ATI FireGL cards
under Windows. I'm currently testing an ATI FireGL X1, but I've been
setting it up under Linux as they have Linux drivers for it, and in our
own lab here we're mostly a Unix shop. I've run VMD on a dual-DVI output
FireGL 4 at NCSA and it worked beautfully when I tested it. I may have
more comments on the FireGL X1 after I've had more time to test it.

Note that most of the professional-level video boards supporting stereo
require an AGP-Pro 50 slot, which limits the range of motherboards you
can use, this may be the same issue as the old 3DLabs cards you mentioned...

Anyway, if you buy from a vendor that'll take returns, you'll be able to
make absolutely sure that you're happy with the card you get. This way
if you want to try a Quadro despite the known problems I describe above,
you'll be safe to return it and try something else if you're not happy.

Thanks,
  John Stone
  vmd_at_ks.uiuc.edu

On Wed, Feb 05, 2003 at 09:47:55AM -0800, Jill Vickery wrote:
> I am trying to set up a PC which will do 3D using stereographics emitter and
> glasses (I know they are expensive but I already have 4 sets so I hate to
> throw them away). We therefore need a graphics card that will work with the
> emitter as well as with the software we will be running, mainly VMD and O.
> We are currently looking at the PNY Quadro4 980XGL 8x AGP card running under
> Windows XP. Does anyone have any experience with this card they could share
> with us? I have seen some mention on the board that the nvidia cards give
> some problems, and I was wondering if this is also the case for the
> Quadro4s? We have already tried several 3D lab oxygen cards and it appears
> their cards are very motherboard dependent, so I would like to steer clear
> of 3Dlabs. Any suggestions on a video card with a 3pin stereo plug would be
> much appreciated!!
>
> Cheers!
> Jill Vickery 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349              
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078