[gmx-users] Re: On the choosing of GPU for MD runs

[Szilárd Páll]

On Mon, Jan 14, 2013 at 7:20 PM, James Starlight <jmsstarlight at gmail.com>wrote:

> 1)As I understood from nvidia site at present time GPU's from the
> tesla serie are the best for the calculations like md. For instasnce
> NVIDIA Tesla C2075 have performance ~ 1 TFLOPS in the
> single-precission calculations. I wounder to know how many 8-core CPU
> must have typical cluster to obtain such performance ? Have someone
> tried to use tesla GPU with gromacs ? What real performance in ns\day
> have been obtained with the explicit solvent systems?
>
>
> 2) Today I performed test gpu-based calculation with 2 different gpu's
> ( GTX 670 vs GT 640). Both of that gpu's have the same GPU frequency
> but GTX 670 has 256 bit memory interface width with ddr5 ram worked on
> higher frequency. As the result I've obtained 50% more perfomance with
> the GTX 670. Does the memory interface width as well as ram frequency
> affect on total GPU performance in addition to GPU frequency?
>
>
As mentioned before, the memory does not matter as much as the number of
processing cores on the GPUs and their frequency.
- GTX 670: 1344 "CUDA cores" (7 multiprocessors * 192 cores) running at 915
Mhz.
- GTX 640: 384 "CUDA cores" (2 multiprocessors * 192 cores) running at 900
Mhz.

The raw GPU performance with our current algorithms has a roughly linear
relationship with the number of cores and frequency, so the raw GPU kernel
performance difference between 670 and 640 should be around 3.5x. It is a
bit surprising that you've only got 50% higher total performance with the
670.

--
Szilárd



> James
>
>
>
> 2013/1/14 James Starlight <jmsstarlight at gmail.com>:
> > Dear Gromacs Users!
> >
> >
> > I wounder to know some detailes about choosing of the gpu for md with
> > gromacs. In particular on what properties of the videoadapter should I
> > pay most attention ? What modern gpu nvidia-series might give best
> > performance (gtx 6xx, tesla or quadro series) ? Could you provide me
> > with some bechmarks besides the information present on the Gromacs web
> > ?
> >
> > For instance with the gpu Geforce GTX 670 + core i5 (4 cores) I have
> > performance 10ns\day for explicit system with 67000 atoms ( protein in
> > tip3p water). Have someone better results with common home-like
> > desktop? :)
> >
> >
> > James
> --
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