diff --git a/n2s3/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/features/logging/SimMongoLog.scala b/n2s3/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/features/logging/SimMongoLog.scala
index ae801b492c389a0400325c2050ccf9bdc1d116ab..31c2d577a5721f9fc58782a5d3f76407f52f9875 100644
--- a/n2s3/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/features/logging/SimMongoLog.scala
+++ b/n2s3/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/features/logging/SimMongoLog.scala
@@ -34,7 +34,7 @@ class SimMongoLog(n2s3 : N2S3,list : IndexedSeq[IndexedSeq[IndexedSeq[Connection
   val USERNAME = ""
   val PASSWORD = ""
   val HOST = "127.0.0.1:27017"
-  val mongoClient: MongoClient = MongoClient("mongodb://"+USERNAME+":"+PASSWORD+"@"+HOST+"/?authSource=admin&readPreference=primaryPreferred")
+  val mongoClient: MongoClient = MongoClient(if (USERNAME != "" && PASSWORD != "") "mongodb://"+USERNAME+":"+PASSWORD+"@"+HOST+"/?authSource=admin&readPreference=primaryPreferred" else "mongodb://"+HOST+"/?authSource=admin&readPreference=primaryPreferred")
   val database: MongoDatabase = mongoClient.getDatabase(name+"-"+time.replaceAll("\\s", "-"))
   var singleLayersDocument = Document()
   var neuroneS,neuroneE = 0
@@ -109,7 +109,7 @@ class SimMongoLog(n2s3 : N2S3,list : IndexedSeq[IndexedSeq[IndexedSeq[Connection
     })
 
     InfoCollection.insertOne(Document(
-      "MaxS" -> (benchmark.getResult.evaluationByMaxSpiking.score * 100.00D) / benchmark.getResult.inputNumber,
+      "Acc" -> (benchmark.getResult.evaluationByMaxSpiking.score * 100.00D) / benchmark.getResult.inputNumber,
       "NLabel" -> NeuronLabel)).subscribe(observer)
       /**
       "FirstS" -> (benchmark.getResult.evaluationByFirstSpiking.score * 100.00D) / benchmark.getResult.inputNumber,
@@ -477,4 +477,4 @@ class ActivityStoreActor(n2s3 : N2S3) extends NetworkActor {
 object GlobalLogVars {
   var ActualInput = ""
   var globalInput = 0
-}
\ No newline at end of file
+}
diff --git a/n2s3_examples/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/apps/ExampleMnist2.scala b/n2s3_examples/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/apps/ExampleMnist2.scala
index 83cfc7d5e35df137c57a0dfec3a6b5aca92432f4..90e189587efe2fc02376a702230bbb162e4df2f9 100644
--- a/n2s3_examples/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/apps/ExampleMnist2.scala
+++ b/n2s3_examples/src/main/scala/fr/univ_lille/cristal/emeraude/n2s3/apps/ExampleMnist2.scala
@@ -60,7 +60,7 @@ object  ExampleMnist2 extends App {
   var log = true
   var prune = false
   var globalIteration = 1
-  var sizeChunk = 500
+  var sizeChunk = 60000
 
   for(x <- 1 to 1) {
     implicit val timeout = Config.longTimeout