X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/hpcc2014.git/blobdiff_plain/0465f42aaa2cd6ca1b5a122e6461818f309140c2..28e01316fd4048f6765d2771d36cd4565cba5421:/hpcc.tex?ds=sidebyside diff --git a/hpcc.tex b/hpcc.tex index 2bb3997..04c5403 100644 --- a/hpcc.tex +++ b/hpcc.tex @@ -561,7 +561,7 @@ $\text{62}^\text{3} = \text{\np{238328}}$ to $\text{150}^\text{3} = \end{mytable} \end{table} -\RC{Du coup la latence est toujours la même, pourquoi la mettre dans la table?} +%\RC{Du coup la latence est toujours la même, pourquoi la mettre dans la table?} %Then we have changed the network configuration using three clusters containing %respectively 33, 33 and 34 hosts, or again by on hundred hosts for all the @@ -650,8 +650,8 @@ Note that the program was run with the following parameters: \item Maximum numbers of outer and inner iterations; \item Outer and inner precisions on the residual error; \item Matrix size $N_x$, $N_y$ and $N_z$; -\item Matrix diagonal value: $6$ (See Equation~(\ref{eq:03})); -\item Matrix off-diagonal value: $-1$; +\item Matrix diagonal value: $6$ (see Equation~(\ref{eq:03})); +\item Matrix off-diagonal values: $-1$; \item Communication mode: asynchronous. \end{itemize} @@ -664,12 +664,12 @@ asynchronous multisplitting compared to GMRES with two distant clusters. With these settings, Table~\ref{tab.cluster.2x50} shows that after setting the bandwidth of the inter cluster network to \np[Mbit/s]{5} and a latency in order of one hundredth of millisecond and a processor power of one GFlops, an efficiency of about \np[\%]{40} is -obtained in asynchronous mode for a matrix size of 62 elements. It is noticed that the result remains +obtained in asynchronous mode for a matrix size of $62^3$ elements. It is noticed that the result remains stable even we vary the residual error precision from \np{E-5} to \np{E-9}. By -increasing the matrix size up to 100 elements, it was necessary to increase the +increasing the matrix size up to $100^3$ elements, it was necessary to increase the CPU power of \np[\%]{50} to \np[GFlops]{1.5} to get the algorithm convergence and the same order of asynchronous mode efficiency. Maintaining such processor power but increasing network throughput inter cluster up to \np[Mbit/s]{50}, the result of efficiency with a relative gain of 2.5 is obtained with -high external precision of \np{E-11} for a matrix size from 110 to 150 side +high external precision of \np{E-11} for a matrix size from $110^3$ to $150^3$ side elements. %For the 3 clusters architecture including a total of 100 hosts, @@ -679,8 +679,8 @@ elements. %(synchronous and asynchronous) is achieved with an inter cluster of %\np[Mbit/s]{10} and a latency of \np[ms]{E-1}. To challenge an efficiency greater than 1.2 with a matrix %size of 100 points, it was necessary to degrade the %inter cluster network bandwidth from 5 to \np[Mbit/s]{2}. -\AG{Conclusion, on prend une plateforme pourrie pour avoir un bon ratio sync/async ??? - Quelle est la perte de perfs en faisant ça ?} +%\AG{Conclusion, on prend une plateforme pourrie pour avoir un bon ratio sync/async ??? + %Quelle est la perte de perfs en faisant ça ?} %A last attempt was made for a configuration of three clusters but more powerful %with 200 nodes in total. The convergence with a relative gain around 1.1 was @@ -704,7 +704,7 @@ reach the following two objectives: \item To test the combination of the cluster and network specifications permitting to execute an asynchronous algorithm faster than a synchronous one. \end{enumerate} -Our results have shown that with two distant clusters, the asynchronous multisplitting is faster to \np[\%]{40} compared to the synchronous GMRES method +Our results have shown that with two distant clusters, the asynchronous multisplitting method is faster to \np[\%]{40} compared to the synchronous GMRES method which is not negligible for solving complex practical problems with more and more increasing size.