X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/mpi-energy2.git/blobdiff_plain/bfe48a883c88e5b63cc724dee3e46d6d18b9a34a..d509f4d19eb0a9dfb0cb8fcc367e63e0e172fd42:/Heter_paper.tex diff --git a/Heter_paper.tex b/Heter_paper.tex index 0203c67..af3d660 100644 --- a/Heter_paper.tex +++ b/Heter_paper.tex @@ -88,9 +88,10 @@ platforms many techniques have been used. Dynamic voltage and frequency scaling consumption. However, lowering the frequency of a CPU might increase the execution time of an application running on that processor. Therefore, the frequency that gives the best trade-off between the energy consumption and the -performance of an application must be selected.\\ -In this paper, a new online frequencies selecting algorithm for heterogeneous -platforms is presented. It selects the frequency which tries to give the best +performance of an application must be selected. + +In this paper, a new online frequency selecting algorithm for heterogeneous +platforms is presented. It selects the frequencies and tries to give the best trade-off between energy saving and performance degradation, for each node computing the message passing iterative application. The algorithm has a small overhead and works without training or profiling. It uses a new energy model for @@ -714,7 +715,7 @@ brute force algorithm. It has a small execution time: for a heterogeneous cluster composed of four different types of nodes having the characteristics presented in Table~\ref{table:platform}, it takes on average \np[ms]{0.04} for 4 nodes and \np[ms]{0.15} on average for 144 nodes to compute the best scaling -factors vector. The algorithm complexity is $O(F\cdot (N \cdot4) )$, where $F$ +factors vector. The algorithm complexity is $O(F\cdot N)$, where $F$ is the number of iterations and $N$ is the number of computing nodes. The algorithm needs from 12 to 20 iterations to select the best vector of frequency scaling factors that gives the results of the next sections. @@ -748,22 +749,22 @@ nodes were connected via an Ethernet network with 1 Gbit/s bandwidth. \caption{Heterogeneous nodes characteristics} % title of Table \centering - \begin{tabular}{|*{7}{l|}} + \begin{tabular}{|*{7}{r|}} \hline Node &Simulated & Max & Min & Diff. & Dynamic & Static \\ type &GFLOPS & Freq. & Freq. & Freq. & power & power \\ & & GHz & GHz &GHz & & \\ \hline - 1 &40 & 2.5 & 1.2 & 0.1 & 20~W &4~W \\ + 1 &40 & 2.50 & 1.20 & 0.100 & \np[W]{20} &\np[W]{4} \\ \hline - 2 &50 & 2.66 & 1.6 & 0.133 & 25~W &5~W \\ + 2 &50 & 2.66 & 1.60 & 0.133 & \np[W]{25} &\np[W]{5} \\ \hline - 3 &60 & 2.9 & 1.2 & 0.1 & 30~W &6~W \\ + 3 &60 & 2.90 & 1.20 & 0.100 & \np[W]{30} &\np[W]{6} \\ \hline - 4 &70 & 3.4 & 1.6 & 0.133 & 35~W &7~W \\ + 4 &70 & 3.40 & 1.60 & 0.133 & \np[W]{35} &\np[W]{7} \\ \hline \end{tabular}