From 6a5acd3fe7e39552b96889fca4a4c8b95cf4b206 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 12 Jul 2014 18:08:55 +0530
Subject: [PATCH] Avoid using PyQt to detect the number of CPUs on windows

---
 src/calibre/__init__.py | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/calibre/__init__.py b/src/calibre/__init__.py
index 6d136c5012..9d599c9cf0 100644
--- a/src/calibre/__init__.py
+++ b/src/calibre/__init__.py
@@ -471,16 +471,18 @@ class CurrentDir(object):
 
 def detect_ncpus():
     """Detects the number of effective CPUs in the system"""
-    import multiprocessing
-    ans = -1
-    try:
-        ans = multiprocessing.cpu_count()
-    except:
-        from PyQt5.Qt import QThread
-        ans = QThread.idealThreadCount()
-    if ans < 1:
-        ans = 1
-    return ans
+    if iswindows:
+        import win32api
+        ans = win32api.GetSystemInfo()[5]
+    else:
+        import multiprocessing
+        ans = -1
+        try:
+            ans = multiprocessing.cpu_count()
+        except Exception:
+            from PyQt5.Qt import QThread
+            ans = QThread.idealThreadCount()
+    return max(1, ans)
 
 
 relpath = os.path.relpath