diff -up src/sage/numerical/backends/coin_backend.pyx.orig src/sage/numerical/backends/coin_backend.pyx
--- src/sage/numerical/backends/coin_backend.pyx.orig	2016-10-20 08:11:54.641546892 -0400
+++ src/sage/numerical/backends/coin_backend.pyx	2016-10-20 08:12:03.505547232 -0400
@@ -756,8 +756,8 @@ cdef class CoinBackend(GenericBackend):
         model.setLogLevel(old_logLevel)
 
         # multithreading
-        import multiprocessing
-        model.setNumberThreads(multiprocessing.cpu_count())
+        #import multiprocessing
+        #model.setNumberThreads(multiprocessing.cpu_count())
 
         model.branchAndBound()