VMD-L Mailing List

From: Sabuj Pattanayek (sabuj.pattanayek_at_Vanderbilt.Edu)
Date: Tue Jan 04 2005 - 16:06:39 CST

Hi,

Ayone know why I would have terrible graphics performance for some of
the newer and older Linux_x86 nvidia drivers except for v1.0.5336 on my
quadro 750 xgl card and only for VMD v1.8.2 (not with any other modeling
programs e.g. chimera, spdbv, ribbons, turbo, o, etc)?

The other driver versions I tested are: 1.0.6229 (latest), 1.0.6111, &
1.0.4365 which is "quadro certified" but all of them give really poor
performance compared to 1.0.5336 in VMD.

These are the settings for all the drivers:

glxinfo | grep direct
direct rendering: Yes

cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: NVIDIA
AGP Rate: 4x
Fast Writes: Enabled
SBA: Enabled

I also tried switching between agpgart and nvidia's agp for all of the
drivers but there is no difference. The system is running under a 2.4.28
kernel. I thought it might be related to the issue below so I included
the forward.

Thanks
Sabuj Pattanayek

John Stone wrote:
> Hi,
> Generally speaking, remote rendering will be significantly slower
> than local rendering, so you only want to do this when you have no
> other choice. This is particularly true for apps that draw a lot of
> geometry using immediate mode OpenGL. We've made a large number of
> changes in VMD 1.8.3 to make it more remote-display friendly (and faster
> in general..) but even so, you'll still notice a big difference between
> local and remote display performance.
>
> You might also experiment with enabling "Display->Cachemode->On" in
> the GUI of VMD 1.8.3b1, this enables a feature which can give a huge
> performance boost on remote displays, tiled displays, etc.
> For the display of a static molecular structure, the display cachemode feature
> should give you anywhere from a 10x to 50x performance boost over normal
> rendering. Some machines also get a performance benefit for local rendering
> when the caching code is enabled, but that's less frequently the case than
> for remote display. Try that out and let us know how it works for you.
>
> John
>
>
> On Tue, Dec 28, 2004 at 03:39:32PM +0100, Greipel.Joachim_at_MH-Hannover.DE wrote:
>
>>Hi All,
>>I am setting up VMD on a DUAL-Opteron machine for rendering on remote
>>X-Servers which run under Linux and are equipped with NVIDA Quadro
>>Graphics and Hardware Stereo.
>>
>>The rendering on the remote machines worked (even stereo display with
>>crystal eyes) but unfortunately it was very (!) slow. I just installed
>>the 1.8.3b1 version and to my surprise the rendering on the remote
>>machines is now acceptably fast.
>>
>>There are slight differences in the startup messages of VMD
>>
>>1.8.3b1 ("fast rendering")
>>
>>Info) Email questions and bug reports to vmd_at_ks.uiuc.edu
>>Info) Please include this reference in published work using VMD:
>>Info) Humphrey, W., Dalke, A. and Schulten, K., `VMD - Visual
>>Info) Molecular Dynamics', J. Molec. Graphics 1996, 14.1, 33-38.
>>Info) -------------------------------------------------------------
>>Info) Multithreading available, 2 CPUs detected.
>>Info) OpenGL renderer: Quadro4 980 XGL/AGP/SSE2
>>Info) Features: STENCIL STEREO RN MDE MTX PP
>>Info) OpenGL Programmable shading is NOT available.
>>Info) Textures: 2-D (4096x4096), 3-D (512x512x512), Multitexture (4)
>>
>>1.8.2 ("slow rendering")
>>
>>Info) http://www.ks.uiuc.edu/Research/vmd/
>>Info) Email questions and bug reports to vmd_at_ks.uiuc.edu
>>Info) Please include this reference in published work using VMD:
>>Info) Humphrey, W., Dalke, A. and Schulten, K., `VMD - Visual
>>Info) Molecular Dynamics', J. Molec. Graphics 1996, 14.1, 33-38.
>>Info) -------------------------------------------------------------
>>Info) Multithreading available, 2 CPUs detected.
>>Info) OpenGL renderer: Quadro4 980 XGL/AGP/SSE2
>>Info) Features: STENCIL STEREO RN MTX
>>Info) Textures: 2-D (4096x4096), 3-D (512x512x512), Multitexture (4)
>>vmd >
>>
>>Is there any rational explanation for this behaviour?
>>Thanks a lot,
>>
>>Joachim Greipel
>>
>>Medizinische Hochschule Hannover
>>Germany
>
>