X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/rce2015.git/blobdiff_plain/22d629e2f878e218fe18011ba785ba6b6ce20d17..f191ea095298626cf15138076b2e26ee4dec9b15:/paper.tex?ds=sidebyside diff --git a/paper.tex b/paper.tex index 26f40cb..24ddab9 100644 --- a/paper.tex +++ b/paper.tex @@ -574,12 +574,15 @@ The execution times between both algorithms is significant with different grid a \end{figure} \subsubsection{Simulations for two different inter-clusters network speeds\\} -In Figure~\ref{fig:02} we present the execution times of both algorithms to solve a 3D Poisson problem of size $150^3$ on two different simulated network $N1$ and $N2$ (see Table~\ref{tab:01}). As it was previously said, we can see from the figure that the Krylov two-stage algorithm is more sensitive the number of clusters than the GMRES algorithm. However, we can notice an interesting behavior of the Krylov two-stage algorithm. It is less sensitive to bad network bandwidth and latency for the inter-clusters links than the GMRES algorithms. This means that the multisplitting methods are more efficient for distributed systems with high latency networks. - - - - -%% The figure shows that the Krylov two-stage algorithm is more sensitive the number of clusters than the GMRES algorithm. +In Figure~\ref{fig:02} we present the execution times of both algorithms to +solve a 3D Poisson problem of size $150^3$ on two different simulated network +$N1$ and $N2$ (see Table~\ref{tab:01}). As previously mentioned, we can see from +this figure that the Krylov two-stage algorithm is sensitive to the number of +clusters (i.e. it is better to have a small number of clusters). However, we can +notice an interesting behavior of the Krylov two-stage algorithm. It is less +sensitive to bad network bandwidth and latency for the inter-clusters links than +the GMRES algorithms. This means that the multisplitting methods are more +efficient for distributed systems with high latency networks. %% In this section, the experiments compare the behavior of the algorithms running on a %% speeder inter-cluster network (N2) and also on a less performant network (N1) respectively defined in the test conditions Table~\ref{tab:02}. @@ -588,8 +591,6 @@ In Figure~\ref{fig:02} we present the execution times of both algorithms to solv %% for both algorithms when using a grid architecture like 4 $\times$ 16 or 8 $\times$ 8: the reduction factor is around $2$. The results depict also that when %% the network speed drops down (variation of 12.5\%), the difference between the two Multisplitting algorithms execution times can reach more than 25\%. -\LZK{J'ai mis que le problème résolu dans la figure 4 est de taille $150^3$. CE, pourrais tu le confirmer?} - \begin{figure}[t] \centering \includegraphics[width=100mm]{cluster_x_nodes_n1_x_n2.pdf}