suite

[Krylov_multi.git] / krylov_multi.tex

diff --git a/krylov_multi.tex b/krylov_multi.tex
index 7a7e809f2375277dff3ee8c0ba7bba161518dcb1..14797c23a146679ff6eb8d9cb98615f751b330ec 100644 (file)
--- a/krylov_multi.tex
+++ b/krylov_multi.tex
@@ -5,6 +5,7 @@
 \usepackage{graphicx}
 \usepackage{algorithm}
 \usepackage{algpseudocode}
 \usepackage{graphicx}
 \usepackage{algorithm}
 \usepackage{algpseudocode}

+\usepackage{multirow}

 
 \algnewcommand\algorithmicinput{\textbf{Input:}}
 \algnewcommand\Input{\item[\algorithmicinput]}
 
 \algnewcommand\algorithmicinput{\textbf{Input:}}
 \algnewcommand\Input{\item[\algorithmicinput]}


@@ -12,6 +13,9 @@
 \algnewcommand\algorithmicoutput{\textbf{Output:}}
 \algnewcommand\Output{\item[\algorithmicoutput]}
 
 \algnewcommand\algorithmicoutput{\textbf{Output:}}
 \algnewcommand\Output{\item[\algorithmicoutput]}
 

+\newcommand{\Time}[1]{\mathit{Time}_\mathit{#1}}
+\newcommand{\Prec}{\mathit{prec}}
+\newcommand{\Ratio}{\mathit{Ratio}}

 
 \title{A scalable multisplitting algorithm for solving large sparse linear systems} 
 \date{}
 
 \title{A scalable multisplitting algorithm for solving large sparse linear systems} 
 \date{}


@@ -352,6 +356,48 @@ obtained for  a 3D Poisson  problem, the number  of iterations is high.  Using a
 preconditioner  it  is   possible  to  reduce  the  number   of  iterations  but
 preconditioners are not scalable when using many cores.
 
 preconditioner  it  is   possible  to  reduce  the  number   of  iterations  but
 preconditioners are not scalable when using many cores.
 

+Doing many experiments  with many cores is  not easy and require to  access to a
+supercomputer  with several  hours for  developping  a code  and then  improving
+it. In the following we presented  some experiments we could achieved out on the
+Hector architecture,  the previous UK's  high-end computing resource,  funded by
+the UK Research Councils, which has been stopped in the early 2014.
+
+In the experiments  we report the size of the 3D  poisson considered
+
+
+The first column  shows the size of the  problem The size is chosen  in order to
+have approximately 50,000 components per core.  The second column represents the
+number of  cores used. In parenthesis,  there is the decomposition  used for the
+Krylov multisplitting. The  third column and the sixth  column respectively show
+the execution time for the GMRES  and the Kyrlow multisplitting code. The fourth
+and  the   seventh  column   describes  the  number   of  iterations.   For  the
+multisplitting  code, the  total number  of inner  iterations is  represented in
+parenthesis.
+
+ We  also give  the other parameters:  the restart  for the GRMES method....
+
+\begin{table}[p]
+\begin{center}
+\begin{tabular}{|c|c||c|c|c||c|c|c||c|} 
+\hline
+\multirow{2}{*}{Pb size}&\multirow{2}{*}{Nb. cores} &  \multicolumn{3}{c||}{GMRES} &  \multicolumn{3}{c||}{Krylov Multisplitting} & \multirow{2}{*}{Ratio}\\
+ \cline{3-8}
+           &                   &  Time (s) & nb Iter. & $\Delta$  &   Time (s)& nb Iter. & $\Delta$ & \\
+\hline
+
+$590^3$ & 4096 (2x2048)        &  462.6    & 55,494    & 4.92e-7  &  74.1    & 1,101(8,211) & 6.62e-08  & 6.25   \\
+\hline
+$743^3$ & 8192 (2x4096)        & 704.4     & 87,822    & 4.80e-07 &  151.2   & 3,061(14,914) & 5.87e-08 & 4.65    \\
+\hline
+$743^3$ & 8192 (4x2048)        & 704.4     & 87,822    & 4.80e-07 &  110.3   & 1,531(12,721) & 1.47e-07& 6.39  \\
+\hline
+
+\end{tabular}
+\caption{CAPTION}
+\label{tab1}
+\end{center}
+\end{table}
+

 \section{Conclusion and perspectives}
 
 Other applications (=> other matrices)\\
 \section{Conclusion and perspectives}
 
 Other applications (=> other matrices)\\