VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Mon Nov 19 2012 - 11:25:48 CST

Pietro,
  One thing I notice is that your GPU only as 128MB of memory.
This is a small enough amount of memory that it could present a
challenge if you've got a few things soaking up GPU RAM.
Have you tried turning off the X11 composite / compiz extension?
The compositing window manager eats GPU memory, so that might
alleviate some of the performance issue you're seeing.
I would try that first thing. If that doesn't work, I could try
giving you a VMD that uses a shallower bit-depth framebuffer and
see if that has any impact.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Mon, Nov 19, 2012 at 05:25:33PM +0100, Pietro Amodeo wrote:
> Hi John,
>
> On Sun, 18 Nov 2012 22:25:27 -0600, John Stone wrote:
> >Hi,
> > Does VMD print any warnings on this machine when it starts?
> >(e.g. compiz compositing manager)
>
> this is the VMD start printout:
>
> Info) VMD for LINUXAMD64, version 1.9.1 (February 1, 2012)
> 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) Free system memory: 3644MB (92%)
> Info) Creating CUDA device pool and initializing hardware...
> Info) Detected 1 available CUDA accelerator:
> Info) [0] GeForce 8400M GS 2 SM_1.1 @ 0.80 GHz, 127MB RAM, KTO,
> OIO, ZCP
> Warning) Detected X11 'Composite' extension: if incorrect display
> occurs
> Warning) try disabling this optional X server feature.
> Info) OpenGL renderer: GeForce 8400M GS/PCIe/SSE2
> Info) Features: STENCIL MSAA(16) MDE CVA MTX NPOT PP PS GLSL(OVFG)
> Info) Full GLSL rendering mode is available.
> Info) Textures: 2-D (8192x8192), 3-D (2048x2048x2048), Multitexture
> (4)
> Info) Dynamically loaded 2 plugins in directory:
> Info) /usr/local/lib/vmd-1.9.1/plugins/LINUXAMD64/molfile
>
> It looks the same as before the updates and it differs from that shown
> on the GT230M box (apart from obvious differences in memory and device)
> only in the GLSL feature that on this latter is GLSL(OVFGS).
>
> >It is quite possible you're hitting a driver bug in the latest
> >driver version.
>
> It's quite possible indeed, since after installing the just-released
> 310.19 stable version of the driver things improved. In fact, now
> discontinuities in motion are reduced to a flickering and the FPS
> counter shows from 11 to 18 fps with a protein+water system loaded and
> different graphic representations.
>
> >
> >Can you send the startup messages VMD prints on this machine?
> >I'm wondering if your OpenGL installation got damaged during
> >the sequence of upgrades you ran.
>
> In general, I manually update NVidia drivers after linux upgrade and
> reboot in non-graphic mode. In this way I never experienced problems,
> except for badly-bugged drivers.
>
>
> Please, let me know if you may need any other info.
>
> Thanks,
> Pietro
>
> >
> >Cheers,
> > John Stone
> > vmd_at_ks.uiuc.edu
> >
> >On Fri, Nov 16, 2012 at 08:44:51PM +0100, Pietro Amodeo wrote:
> >>Hi,
> >>
> >>after a kernel upgrade (to 3.6.6-1) on a Fedora 16 laptop (Intel
> >>Core
> >>Duo, 4GB RAM, NVidia 8400M GS) we had to upgrade NVIDIA driver from
> >>295.59 to 304.64. The result is a terribly slow VMD 1.9.1
> >>(practically
> >>unusable) displaying <8 fps with no molecule loaded!!!. Things
> >>slightly
> >>improve with beta driver 310.14 (<=15 fps no mol loaded), but
> >>usability
> >>is still rather poor (not fluid).
> >>
> >>Previously, witn NVidia 295.XX drivers, VMD 1.9.1 worked flawlessly
> >>on
> >>the same laptop. However, with 304.64 or 314.14 all other tested
> >>OpenGL
> >>programs works correctly and no error message is issued in Xorg.log
> >>or
> >>when starting VMD.
> >>
> >>Moreover, VMD 1.9.1 works flawlessly on a Intel i7+NVidia Gt230M
> >>laptop
> >>with the same FC16+kernel 3.6.6-1 +driver 304.64 combination.
> >>
> >>
> >>Thanks in advance for any hint/help.
> >>
> >>Pietro
> >>On this laptop
> >>-- 

-- 
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