568K mesh: Grid performance summary

Shown in Table 16 are the performances for different combinations of MecaGRID clusters using the 568K mesh relative to the nina times with the -O1 and -O3 options. Also shown for comparison are the performances for the 262K mesh.

Table 16: Globus performance summary: 262K versus 568K

	262K	568K
Name of cluster(s)	-O1	-O1	-O3
nina	1.0	1.0	1.0
iusti	1.0	0.8	0.9
pf	1.7	1.4	1.9
cemef	2.3	1.9	1.9
nina-pf	1.2	1.3	1.6
inter cluster
nina-iusti	1.9	2.2	5.8
nina-cemef	1.7	2.4	3.7
pf-iusti	2.5	2.4	4.0
pf-cemef	2.2	2.6	7.3
iusti-cemef	2.9	3.8	6.8

Regarding the shock-bubble test case with the 568K vertices mesh, the following observations are made:

1. The IUSTI cluster's performed 20 percent faster than the INRIA-nina cluster.

2. The INRIA-pf cluster gives a slightly better performance than the CEMEF cluster (1.4 and 1.9), showing better a than expected performance relative to the INRIA-nina cluster.

3. Inter-cluster Grid computations involving the CEMEF cluster tend to be the least efficient.

4. The inter-cluster performances relative to nina using the -O1 compile option are better than with the -O3 compile option. This occurs due to a larger Work/processor when compiled with the -O1 option and therefore a smaller Communication/Work time ratio. A way of decreasing this ratio using the -O3 compile option is to increase the mesh size holding the number of CPUs fixed.