diff --git a/libethash-cl/ethash_cl_miner.h b/libethash-cl/ethash_cl_miner.h
index 8f7594be5..d1cb53ef9 100644
--- a/libethash-cl/ethash_cl_miner.h
+++ b/libethash-cl/ethash_cl_miner.h
@@ -20,7 +20,7 @@
 class ethash_cl_miner
 {
 private:
-	enum { c_maxSearchResults = 63, c_bufferCount = 2, c_hashBatchSize = 1024, c_searchBatchSize = 1024 * 16 };
+	enum { c_maxSearchResults = 63, c_bufferCount = 2, c_hashBatchSize = 1024 };
 
 public:
 	struct search_hook
diff --git a/libethcore/Ethash.cpp b/libethcore/Ethash.cpp
index 9ec6dd71f..d24c8454e 100644
--- a/libethcore/Ethash.cpp
+++ b/libethcore/Ethash.cpp
@@ -55,7 +55,7 @@ namespace eth
 {
 
 const unsigned Ethash::defaultLocalWorkSize = 64;
-const unsigned Ethash::defaultGlobalWorkSizeMultiplier = 512; // * CL_DEFAULT_LOCAL_WORK_SIZE
+const unsigned Ethash::defaultGlobalWorkSizeMultiplier = 4096; // * CL_DEFAULT_LOCAL_WORK_SIZE
 const unsigned Ethash::defaultMSPerBatch = 0;
 const Ethash::WorkPackage Ethash::NullWorkPackage = Ethash::WorkPackage();