From: couturie Date: Thu, 7 May 2015 12:19:45 +0000 (+0200) Subject: correction expé X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/rce2015.git/commitdiff_plain/6cf9ae48517bcca32ee10fc0e2140e3df0386bd7?hp=--cc correction expé --- 6cf9ae48517bcca32ee10fc0e2140e3df0386bd7 diff --git a/paper.tex b/paper.tex index 0df781f..6ac52c3 100644 --- a/paper.tex +++ b/paper.tex @@ -386,8 +386,6 @@ In addition, the following arguments are given to the programs at runtime: \item maximum number of restarts for the Arnorldi process in GMRES method, \item execution mode: synchronous or asynchronous. \end{itemize} -\LZK{CE pourrais tu vérifier et confirmer les valeurs des éléments diag et off-diag de la matrice?} -\RCE{oui, les valeurs de diag et off-diag donnees sont ok} It should also be noticed that both solvers have been executed with the Simgrid selector \texttt{-cfg=smpi/running\_power} which determines the computational power (here 19GFlops) of the simulator host machine. @@ -496,7 +494,7 @@ and between distant clusters. This parameter is application dependent. In the scope of this paper, our first objective is to analyze when the Krylov Multisplitting method has better performance than the classical GMRES -method. With a synchronous iterative method, better performance mean a +method. With a synchronous iterative method, better performance means a smaller number of iterations and execution time before reaching the convergence. For a systematic study, the experiments should figure out that, for various grid parameters values, the simulator will confirm the targeted outcomes, @@ -521,7 +519,7 @@ architectures and scaling up the input matrix size} Input matrix size & N$_{x}$ x N$_{y}$ x N$_{z}$ =150 x 150 x 150\\ %\hline - & N$_{x}$ x N$_{y}$ x N$_{z}$ =170 x 170 x 170 \\ \hline \end{tabular} -\caption{Test conditions: Various grid configurations with the input matix size N$_{x}$=150 or N$_{x}$=170 \RC{je ne comprends pas la légende... Ca ne serait pas plutot Characteristics of cluster (mais il faudrait lui donner un nom)}} +\caption{Test conditions: various grid configurations with the input matix size N$_{x}$=150 or N$_{x}$=170 \RC{N2 n'est pas défini..}\RC{Nx est défini, Ny? Nz?}} \label{tab:01} \end{center} \end{table} @@ -529,8 +527,6 @@ architectures and scaling up the input matrix size} -%\RCE{J'ai voulu mettre les tableaux des données mais je pense que c'est inutile et ça va surcharger} - In this section, we analyze the performance of algorithms running on various grid configurations (2x16, 4x8, 4x16 and 8x8). First, the results in Figure~\ref{fig:01} @@ -546,7 +542,7 @@ multisplitting method. \begin{center} \includegraphics[width=100mm]{cluster_x_nodes_nx_150_and_nx_170.pdf} \end{center} - \caption{Various grid configurations with the input matrix size N$_{x}$=150 and N$_{x}$=170} + \caption{Various grid configurations with the input matrix size N$_{x}$=150 and N$_{x}$=170\RC{idem}} \label{fig:01} \end{figure} @@ -556,7 +552,7 @@ grid architectures, even with the same number of processors (for example, 2x16 and 4x8). We can observ the low sensitivity of the Krylov multisplitting method (compared with the classical GMRES) when scaling up the number of the processors in the grid: in average, the GMRES (resp. Multisplitting) algorithm performs -$40\%$ better (resp. $48\%$) when running from 2x16=32 to 8x8=64 processors. +$40\%$ better (resp. $48\%$) when running from 2x16=32 to 8x8=64 processors. \RC{pas très clair, c'est pas précis de dire qu'un algo perform mieux qu'un autre, selon quel critère?} \subsubsection{Running on two different inter-clusters network speeds \\} @@ -569,16 +565,15 @@ $40\%$ better (resp. $48\%$) when running from 2x16=32 to 8x8=64 processors. - & N2 : bw=1Gbs-lat=5.10$^{-5}$ \\ Input matrix size & N$_{x}$ x N$_{y}$ x N$_{z}$ =150 x 150 x 150\\ \hline \end{tabular} -\caption{Test conditions: Grid 2x16 and 4x8 - Networks N1 vs N2} +\caption{Test conditions: grid 2x16 and 4x8 with networks N1 vs N2} \label{tab:02} \end{center} \end{table} These experiments compare the behavior of the algorithms running first on a -speed inter-cluster network (N1) and also on a less performant network (N2). -Figure~\ref{fig:02} shows that end users will gain to reduce the execution time -for both algorithms in using a grid architecture like 4x16 or 8x8: the -performance was increased by a factor of $2$. The results depict also that when +speed inter-cluster network (N1) and also on a less performant network (N2). \RC{Il faut définir cela avant...} +Figure~\ref{fig:02} shows that end users will reduce the execution time +for both algorithms when using a grid architecture like 4x16 or 8x8: the reduction is about $2$. 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\%. %\RC{c'est pas clair : la différence entre quoi et quoi?} %\DL{pas clair} @@ -589,7 +584,7 @@ the network speed drops down (variation of 12.5\%), the difference between t \begin{figure} [ht!] \centering \includegraphics[width=100mm]{cluster_x_nodes_n1_x_n2.pdf} -\caption{Grid 2x16 and 4x8 - Networks N1 vs N2} +\caption{Grid 2x16 and 4x8 with networks N1 vs N2} \label{fig:02} \end{figure} %\end{wrapfigure} @@ -605,7 +600,7 @@ the network speed drops down (variation of 12.5\%), the difference between t Network & N1 : bw=1Gbs \\ %\hline Input matrix size & N$_{x}$ x N$_{y}$ x N$_{z}$ =150 x 150 x 150\\ \hline \end{tabular} -\caption{Test conditions: Network latency impacts} +\caption{Test conditions: network latency impacts} \label{tab:03} \end{table}