to read the codes available in the PETSc sources. Those problems have been
chosen because they are scalable with many cores which is not the case of other problems that we have tested.
-In the following larger experiments are described on two large scale architectures: Curie and Juqeen... {\bf description...}\\
+In the following larger experiments are described on two large scale
+architectures: Curie and Juqeen. Both these architectures are supercomputer
+composed of 80,640 cores for Curie and 458,752 cores for Juqueen. Those machines
+are respectively hosted by GENCI in France and Jülich Supercomputing Centre in
+Germany. They belongs with other similar architectures of the PRACE initiative (
+Partnership for Advanced Computing in Europe) which aims at proposing high
+performance supercomputing architecture to enhance research in Europe. The Curie
+architecture is composed of Intel E5-2680 processors at 2.7 GHz with 2Gb memory
+by core. The Juqueen architecture is composed of IBM PowerPC A2 at 1.6 GHz with
+1Gb memory per core.
+
{\bf Description of preconditioners}\\
