VMD-L Mailing List

From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Sun Jan 24 2010 - 13:09:26 CST

On Sun, Jan 24, 2010 at 11:57 AM, Edelmiro Moman
<edelmiro.moman_at_gmail.com> wrote:
> Hello,
>
> I am going to buy a HPC to serve both as a graphical workstation and a
> GPU/CPU computing system. The system has two quadcore CPUs and three
> NVIDIA Tesla C1060 GPUs.

would suggest to check out the NAMD mailing list archive.
some important issues of multi-GPU configurations were
discussed there recently, and you should confirm whether
your are covering all potential problems.

>
> As for the graphics card, the retailer is offering a few options:
>
>        1  Quadro® 290 NVS PCI-E 1X                             109.554 €
>        1  Quadro® 450 NVS PCI-E 16X 512MB                397.296 €
>        1  NVIDIA TESLA C1060 Compute Board              1091.2 €
>        2  NVIDIA TESLA C1060 Compute Board              2182.4 €
>        3  NVIDIA TESLA C1060 Compute Board              3273.6 €
>        4  NVIDIA TESLA C1060 Compute Board              4364.8 €
>        1  NVIDIA GeForce™ GTX295 1,792GB PCIe 2.0    404.24 €
>        2  NVIDIA GeForce™ GTX295 1,792GB PCIe 2.0        808.48 €
>        1  NVIDIA Quadro® FX 3800 PCIE 1GB                703.08 €
>        1  NVIDIA Quadro® FX 4800 PCIe 2.0 1,5GB         1385.748 €
>        1  NVIDIA Quadro® FX 5800 PCIe 2.0 4GB           2519.748 €
>
> I already have 3 Teslas and thefore there is only room for a single
> graphics card. I am hesitating between NVIDIA GeForce™ GTX295 and
> NVIDIA Quadro® FX 3800.
>
> I have checked an NVIDIA report from 2001 which I believe to be a bit
> outdated and also several gamers forums discussing the GeForce vs
> Quadro question. However, they do not address the specific molecular
> graphics needs. I have also noticed that the issue has been discussed
> in this mailing list before, but in all cases the Quadro option was
> discarded beforehand.

... and for a very good reason: the quadro cards have an abysmal
price/performance ratio compared to geforce cards.

> I have a few questions:
>
> 1) Does the GTX295 support quad stereo? (I also plan to purchase a
> couple of 3D monitors)

no. only quadro cards support quad-buffered stereo.

> 2) Are really the FXs more suitable for interactive rendering in VMD
> (macromolecular surfaces, for instance) or there is really little
> difference between Quadro and GeForce to that respect?

in terms of performance you have to consider how much of the
work is done on the CPU and how much on GPU. if you have lots
of VDW spheres, you benefit more from the faster GPU, same goes
for transparency. if you use a lines representation, performance is
basically CPU performance.

> 3) What about high-quality rendering or movie making?

the highest quality rendering is done with external renderers
and, e.g., tachyon only uses the CPU. GPUs don't easily
lend themselves to raytracing.

> 4) Is it worthy buying the FX3800 or would I be better served with the GTX295?

the GTX 295 is practically two GTX 260 glued together. if you want the
best graphics performance, you want a GTX 285.. the FX 3800 will
be significantly slower than either. you need the FX5800 to come into
the performance range of the high end Geforce GTX cards. you can
look up the specs on the nvidia page and compare the performance
(number of shaders, clock rates)..

> 5) Would it be worthy upgrading to a FX4800?

depends on how much money you want to spend.

> 6) Is there a better option?

"good" or "bad" depends on what you want to optimize for
and what the capability of your mainboard and application
software are.

the absolute fastest GPU is the GTX 285. if you want the
most GPUs per box, you have to use the GTX 295's.. stereo
with VMD requires quadro. the main difference of the tesla
and quadro to the geforce is that they are more tightly validated
and have more memory on the GPU..

cheers,
    axel.
> Best regards,
>
> --
> Edelmiro Moman, PhD
> ProSciens, Computing & Molecular Sciences
> 2 rue du Palais de Justice
> L-1841 Luxembourg
>
> Phone: +352 2728 2588
> E-mail: edelmiro.moman_at_gmail.com
> E-mail: moman_at_prosciens.com
> Website: http://www.edelmiromoman.eu/
> Website: http://www.prosciens.com/
>
> 

-- 
Dr. Axel Kohlmeyer    akohlmey_at_gmail.com
Institute for Computational Molecular Science
College of Science and Technology
Temple University, Philadelphia PA, USA.