On centos6 instruction, remove the comment about 1 thread as it is linked again the parallel atlas!

doc/install_centos6.txt

@@ -15,12 +15,6 @@ Easy Installation of an optimized Theano on CentOS 6
     investing money (i.e. buying a license to a proprietary BLAS
     implementation), it is possible to gain further performance.
 
-.. note::
-
-    These instructions will result in Theano using only 1 thread for all BLAS
-    function calls. See the note above; other BLAS implementations can employ
-    multithreading to speed up computation.
-
 .. note::
 
    If you are behind a proxy, you must do some extra configuration steps