Changes between Version 12 and Version 13 of ParallelismPerformances

Timestamp:

2012-11-22T15:39:41+01:00 (11 years ago)

Author:

dsolyga

Comment:

--

ParallelismPerformances

@@ -161 +161 @@
 
 After first tests, the results are OK, we have the same performance when we set 2 in flincom module. 
- 
+See ticket #40.
+
+
+=== Methodology (22/11/2012) ===
+
+In order to study both the influence of the IO patches and the Load balance file, I make a survey using the following setup :
+ * NCC forcing file : 360*180, 15238 land points
+ * Loop 10 times over the same year to study the influence of the Load balance file.
+ * sechiba_hist_level = 4
+ * stomate_hist_level = 5
+ * Monthly outputs
+ * Tests done on Curie
+I calculate the average computation time over the 5 last runs. So we are sure that the load balance file is "stabilized".
+|| Nb processors || Average time without patches (seconds)   || Average time with patches (seconds) ||   Time gain (ratio) ||
+||  8            ||    920.69                                || 790.15                           ||  ~15%                     || 
+||  16           ||    495.84                                ||  406.85                         ||   ~18%                     ||
+||  32           ||    573.00                                ||  234.4                          ||      ~59%                  ||
+||  48           ||    510.61                                ||  202.55                         ||    ~61%                     ||   
+||  64           ||    433.53                                ||  191.90                         ||    ~55%                     ||   
+Notice that the patch is significant for a high number of processors (>16). For 32 and 48 processors, the gain is about 60% (it seems that it is the optimal for NCC).
+After 48, the gain diminished. [[BR]]
+For a half degree meteorological data, we may expect to use until 192 processors !