Re: [AMBER] what are the benefits of cuda9 vs. 8 with amber 18?

From: David A Case <david.case.rutgers.edu>
Date: Wed, 9 May 2018 10:18:28 -0400

On Tue, May 08, 2018, Chris Neale wrote:
>
> I've compiled amber18 with cuda8 and gcc 4.x and I'm testing that
> throughput now in comparison to the same setup with amber16. As I work
> through these tests, I wonder if anyone has any data to indicate if cuda9
> offers any improvement. Also, do more recent versions of gcc or openmpi
> offer any improvements in amber18 performance?

I'm not the best person to reply here, but will get started, and hope
that others can correct what I say.

Cuda version 9 is required for Volta based GPUs. More information is
available in the "Supported GPUs" section at
http://ambermd.org/gpus/index.htm. We are in the process of updating
that page for Amber18. Note that Fermi cards (Hardware version 2.0) are
no longer supported in Amber18, so hang on to Amber16 if you plan to use
that (rather old, by now) hardware.

Basically, MD performance depends a *lot* on the hardware you have, but
very little on which version of cuda, gcc or MPI you use. Updated
benchmarks are coming, but people that are really interested in small
percentage changes will need to carry out their own tests, probably on
the exact systems they are using.

>
> I guess I'm just trying to figure out if there is at the moment any
> performance-based motivation to move from amber16 to amber18 (we already
> bought amber18, I'm just hesitant to actually switch untill there is a good
> motivation). Presumably the next gen of GPUs will give extra advantage with
> amber18 over amber16 in any event.

We hope/expect to issue a significant performance update for Amber18
cuda code this summer. But right now, the difference in performance is
small between Amber16 and Amber18, (assuming you have a fully-updated
version of Amber16.) [Note: I myself am waiting for the updated
benchmark suite results to be posted, since Amber16 vs. 18 diffs are
probably not uniform across the four generations of cards (Kepler,
Maxwell, Pascal and Volta) that we support.] If you have both versions
of the codes, you can try some quick tests on your favorite systems and
see what you find.

There *are* significant addtions in Amber18 to the features that are
supported: see http://ambermd.org/AmberMD.php.

....dac


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Received on Wed May 09 2018 - 07:30:02 PDT
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