From: lam nguyen (lamvn08_at_gmail.com)
Date: Fri Nov 18 2011 - 12:43:30 CST

Thanks John,

By doing what you suggested, the memory is improved a lot even though VMD
still shows MSAA(16). It's great that now I can open many windows.

However there is still another problem that I did not mention previously.
When I rotate the object in VMD, the window freezes after few moves without
affecting other programs. I would have to click at another window - any
window, to "activate" the VMD window again. But the problem persists. I
have to keep on clicking at another windows to be able to rotate the object
to the viewing angle I want.

This seems a strange behavior. Anyone has experienced this?

Lam

On Fri, Nov 18, 2011 at 9:18 AM, John Stone <johns_at_ks.uiuc.edu> wrote:

> Lam,
> Okay, I see one thing that may explain the memory use issue you're
> having:
>
> On Thu, Nov 17, 2011 at 12:20:41PM -0800, lam nguyen wrote:
> [...]
> > Info) OpenGL renderer: Quadro FX 580/PCI/SSE2
> > Info) Features: STENCIL MSAA(16) MDE CVA MTX NPOT PP PS GLSL(OVF)
>
> The MSAA(16) indicates that your display driver is using 16 antialiasing
> samples per pixel in the VMD OpenGL window. This is 4 times higher than is
> normally used, and for each sample more GPU memory is used...
>
> I would suggest that you try force-disabling multisample antialiasing
> on your GPU and see if the memory usage is significantly decreased.
> You should be able to do this using a command like the ones at the
> top of this NVIDIA documentation page:
>
> http://us.download.nvidia.com/XFree86/Linux-x86_64/285.05.09/README/openglenvvariables.html
>
> Try this:
> nvidia-settings --assign FSAA=0 --assign FSAAAppControlled=0 --assign
> FSAAAppEnhanced=0
>
> If you set that and then re-run VMD, how does it affect your GPU memory
> use?
>
> To revert to your previous antialiasing setting, do this:
> nvidia-settings --assign FSAA=5 --assign FSAAAppControlled=1 --assign
> FSAAAppEnhanced=0
>
> To set it for something that's a potential compromise, try this:
> nvidia-settings --assign FSAA=5 --assign FSAAAppControlled=0 --assign
> FSAAAppEnhanced=1
>
> Cheers,
> John Stone
> vmd_at_ks.uiuc.edu
>
> --
> NIH Resource for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> http://www.ks.uiuc.edu/Research/vmd/ Fax: 217-244-6078
>