VMD-L Mailing List

From: Cara Kreck (cara_a_k_at_hotmail.com)
Date: Thu Aug 28 2014 - 02:33:13 CDT

Hi John,

I tried running glxgears remotely on the GPU cluster, CPU cluster and RHEL workstations from MobaXTerm. In these tests it always reported a framerate of ~60fps, but the gears did not appear to move. This even happened when I ran it from the RHEL workstation that remotely runs VMD perfectly instead of MobaXTerm.

I couldn't find any info on GLX in the MobaXTerm documentation, but it does say that it supports OpenGL. While looking through the options, I found a way to disable hardware rendering in MobaXTerm. This seems to have fixed the problem. glxgears now works properly on both clusters (though strangely enough not the workstation) with a framerate of ~160fps when run from MobaXTerm, while VMD works on all systems from MobaXTerm.

I'm glad to get it working, but I'm still curious as to what is causing the inconsistencies. Why did VMD work on the CPU cluster with hardware acceleration, whereas glxgears didn't? Why did hardware acceleration cause VMD problems on the GPU cluster but not the CPU cluster? Why is it that the only computer that could handle hardware acceleration for VMD on the GPU cluster, is the one with the oldest graphics card and still can't display glxgears properly (with or without LIBGL_ALWAYS_SOFTWARE)? It would be great if anyone here could shed any light on this.

At least it was an easy fix and should come in handy for anyone else having trouble with remote visualisation using Windows.

Thanks,

Cara

> Date: Wed, 27 Aug 2014 11:56:20 -0500
> From: johns_at_ks.uiuc.edu
> To: cara_a_k_at_hotmail.com
> CC: vmd-l_at_ks.uiuc.edu
> Subject: Re: vmd-l: Remote visualisation inconsistency
>
> Cara,
> Are you able to run "glxgears" on your cluster and remotely display it?
> If not, then you would not be able to run VMD either. You need to make
> sure that your Windows MobaXTerm software actually supports GLX protocol
> (required by OpenGL). Most of the free/cheap X11 emulators for Windows
> don't implement GLX, or they implement a small subset that is insufficient
> for sophisticated OpenGL apps like VMD. If you can run the "glxgears"
> program that comes with linux, you would at least have demonstrated that
> it might be possible to run VMD, but if that much doesn't work, then you'll
> have to find a different X11 package for your Windows 7 machine.
>
> An alternative to these methods is to use VirtualGL, which while not
> perfect, is considerably better than using raw X11 protocol in most cases:
> http://www.virtualgl.org/
>
> Cheers,
> John Stone
> vmd_at_ks.uiuc.edu
>
> On Thu, Aug 28, 2014 at 12:37:39AM +0800, Cara Kreck wrote:
> > Hi,
> >
> > We're trying to get VMD to run remotely on a GPU cluster (RHEL) from our
> > Windows 7 workstations using MobaXTerm. VMD was compiled from source on
> > the GPU cluster in order to get it to run with CUDA 5. Remote
> > visualisation using MobaXTerm works on a CPU cluster we have access to and
> > this is the info I get there:
> >
> > Info) VMD for LINUXAMD64, version 1.9.1 (November 19, 2013)
> > 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, 12 CPUs detected.
> > Info) Free system memory: 13839MB (77%)
> > Warning) Detected X11 'Composite' extension: if incorrect display occurs
> > Warning) try disabling this optional X server feature.
> > Info) OpenGL renderer: Quadro 600/PCIe/SSE2
> > Info) Features: STENCIL MSAA(16) MDE MTX NPOT PP PS
> > Info) GLSL rendering mode is NOT available.
> > Info) Textures: 2-D (18x17), 3-D (18x17x18), Multitexture (4)
> >
> > The only things that seems special about the setup here is the unusually
> > low texture numbers (is this due to the limited graphics ability of the
> > remote CPUs?) and setting environment variable LIBGL_ALWAYS_INDIRECT=y.
> > However, if I try to use the same Windows workstation to run VMD on the
> > GPU cluster I get this:
> >
> > Info) VMD for LINUXAMD64, version 1.9.1 (August 19, 2014)
> > 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, 4 CPUs detected.
> > Info) Free system memory: 7062MB (89%)
> > Info) Creating CUDA device pool and initializing hardware...
> > Info) Detected 2 available CUDA accelerators:
> > Info) [0] Tesla C1060 30 SM_1.3 @ 1.30 GHz, 4.0GB RAM, OIO, ZCP
> > Info) [1] Tesla C1060 30 SM_1.3 @ 1.30 GHz, 4.0GB RAM, OIO, ZCP
> > Warning) Detected X11 'Composite' extension: if incorrect display occurs
> > Warning) try disabling this optional X server feature.
> > XRequest.146: GLXBadRenderRequest 0x0
> > Info) OpenGL renderer: Quadro 600/PCIe/SSE2
> > Info) Features: STENCIL MSAA(16) MDE MTX NPOT PP PS GLSL(OVFG)
> > XRequest.146: BadRequest (invalid request code or no such operation)
> > 0xa00001
> > XRequest.146: BadRequest (invalid request code or no such operation)
> > 0xa00001
> > XRequest.146: BadRequest (invalid request code or no such operation)
> > 0xa00001
> > XRequest.146: GLXBadRenderRequest 0x0
> > XRequest.146: GLXBadLargeRequest 0xfd
> > XRequest.146: GLXBadLargeRequest 0x2
> > XRequest.146: GLXBadRenderRequest 0x0
> > XRequest.146: BadRequest (invalid request code or no such operation) 0x0
> > XRequest.146: GLXBadRenderRequest 0x0
> > XRequest.146: BadRequest (invalid request code or no such operation) 0x0
> > Warning) GPU driver failed to compile shader:
> > Warning) /usr/local/vmd-1.9.1/shaders/vmd
> > Warning) This GPU/driver is buggy, or doesn't fully implement GLSL--_2e4ecd4d-d371-4752-8020-7d611b08fd73_--