(no commit message)

diff --git a/MagickCore/thread-private.h b/MagickCore/thread-private.h
index 0a56e154c6e5b398412f4249174274de5f3cd093..24e66a57a838f29674363958fafe3347e32c8446 100644 (file)
--- a/MagickCore/thread-private.h
+++ b/MagickCore/thread-private.h
@@ -35,7 +35,8 @@ extern "C" {
       ((rows) > WorkloadThreshold()))) && ((MagickSizeType) \
       ((columns)*(rows)) > (WorkloadThreshold()*WorkloadThreshold())) && \
       (expression)) \
-    num_threads(GetMagickResourceLimit(ThreadResource))
+    num_threads(GetMagickResourceLimit(ThreadResource)/ \
+      (GetImagePixelCacheType(image) == DiskCache ? 2 : 1))
 
 #if (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ > 10))
 #define MagickCachePrefetch(address,mode,locality) \