[CP2K-user] [CP2K:10946] cp2k on 10 GbE

[Tiziano Müller]

Hi Mike

On 12.11.18 18:01, Mike Ruggiero wrote:
> Hello cp2k community - I have recently setup a small computing cluster, 
> with 20-24 core server nodes linked via 10 GbE connections. While 
> scaling on single nodes is as it should be (i.e., nearly linear), I get 
> very little-to no scale up when performing multiple node simulations. 
> After digging around, it seems that this is relatively well known for 
> cp2k, but I'm curious if anyone has had any success on using cp2k over 
> 10 GbE connections. Any advice would be greatly appreciated!

I do not have any experience when it comes to building clusters with 10 
GbE, but reading up on the topic [1], [2] it seems that you should get 
limited speed-up for up to 8 nodes. But you have to be careful about the 
configuration for MPI (RoCE, Intel implementation if you have Intel 
hardware), plus the benchmarks were only conducted for one specific case 
(H2O-128).

Based on those papers (check also the results from other codes with 
different methods) it seems that with 10 GbE the scaling depends even 
stronger on the exact method used in your simulation than with IB.
So, unless you can share your specific use case and the benchmarks you 
have performed yourself I doubt that you will get more information.

Best regards,
Tiziano

[1] 
http://www.hpcadvisorycouncil.com/pdf/CP2K_Analysis_and_Profiling_Intel_E5.pdf
[2] http://www.hpcadvisorycouncil.com/pdf/IB_and_10GigE_in_HPC.pdf

-- 
Tiziano Müller
University of Zurich
Department of Chemistry
Winterthurerstrasse 190
CH-8057 Zürich

Tel: +41 44 63 54234
www.chem.uzh.ch
tiziano... at chem.uzh.ch