diff --git a/_modules/main_utils.py b/_modules/main_utils.py
index c3542e9b787e5c6fbc1dd111bce171cca1c157ed..682d8e7230720381b4b00f5021c27bf509225d2d 100644
--- a/_modules/main_utils.py
+++ b/_modules/main_utils.py
@@ -279,16 +279,16 @@ class InputDerivedDataArgs:
 # Here gather user input parameters and former global variable that define how the data will be processed from a technical point of view (ex: multicore,gpu...)
 class technicalParms:
     def __init__(self,core,gpu,mean):
-        if gpu != 0 and core != 1:
-            print "Choose either multicore or gpu!"
-            exit(1)
-        self.core=core
+        self.core = core
         if core == None:
             self.core = 1
+        if gpu ==True and self.core > 1:
+            print "Choose either multicore or gpu!"
+            exit(1)
         self.limit_coverage = max(50, mean * 2) / self.core
         self.gpu=gpu
         if gpu == None:
-            self.gpu = 0
+            self.gpu = False
 
 
 # Checks options consistency and instantiates data structure for main.