diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8c4bd8b98..95dbdf9ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -173,9 +173,11 @@ endforeach()
 enable_testing()
 add_subdirectory(utest)
 
-# Add threading library to linker
-find_package(Threads)
-target_link_libraries(${OpenBLAS_LIBNAME} ${CMAKE_THREAD_LIBS_INIT})
+if (USE_THREAD)
+  # Add threading library to linker
+  find_package(Threads)
+  target_link_libraries(${OpenBLAS_LIBNAME} ${CMAKE_THREAD_LIBS_INIT})
+endif()
 
 if (NOT MSVC)
   # Build test and ctest
diff --git a/cmake/c_check.cmake b/cmake/c_check.cmake
index 2249a873f..4ac661f47 100644
--- a/cmake/c_check.cmake
+++ b/cmake/c_check.cmake
@@ -26,14 +26,8 @@
 
 # N.B. c_check (and ctest.c) is not cross-platform, so instead try to use CMake variables.
 set(FU "")
-if(APPLE)
-set(FU "_")
-elseif(MSVC AND ${CMAKE_C_COMPILER_ID} MATCHES "Clang")
-set(FU "")
-elseif(MSVC)
-set(FU "_")
-elseif(UNIX)
-set(FU "")
+if (APPLE OR (MSVC AND NOT ${CMAKE_C_COMPILER_ID} MATCHES "Clang"))
+  set(FU "_")
 endif()
 
 # Convert CMake vars into the format that OpenBLAS expects
@@ -42,43 +36,59 @@ if (${HOST_OS} STREQUAL "WINDOWS")
   set(HOST_OS WINNT)
 endif ()
 
-# added by hpa - check size of void ptr to detect 64-bit compile
-if (NOT DEFINED BINARY)
-  set(BINARY 32)
-  if (CMAKE_SIZEOF_VOID_P EQUAL 8)
-    set(BINARY 64)
-  endif ()
-endif ()
+if(CMAKE_COMPILER_IS_GNUCC AND WIN32)
+    execute_process(COMMAND ${CMAKE_CXX_COMPILER} -dumpmachine
+              OUTPUT_VARIABLE OPENBLAS_GCC_TARGET_MACHINE
+              OUTPUT_STRIP_TRAILING_WHITESPACE)
+    if(OPENBLAS_GCC_TARGET_MACHINE MATCHES "amd64|x86_64|AMD64")
+      set(MINGW64 1)
+    endif()
+endif()
 
-if (BINARY EQUAL 64)
-  set(BINARY64 1)
-else ()
-  set(BINARY32 1)
-endif ()
+# Pretty thorough determination of arch. Add more if needed
+if(CMAKE_CL_64 OR MINGW64)
+  set(X86_64 1)
+elseif(MINGW OR (MSVC AND NOT CMAKE_CROSSCOMPILING))
+  set(X86 1)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc")
+  set(PPC 1)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "amd64.*|x86_64.*|AMD64.*")
+  set(X86_64 1)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "i686.*|i386.*|x86.*|amd64.*|AMD64.*")
+  set(X86 1)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(arm.*|ARM.*)")
+  set(ARM 1)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64.*|AARCH64.*)")
+  set(ARM64 1)
+endif()
 
-# CMake docs define these:
-# CMAKE_SYSTEM_PROCESSOR - The name of the CPU CMake is building for.
-# CMAKE_HOST_SYSTEM_PROCESSOR - The name of the CPU CMake is running on.
-#
-# TODO: CMAKE_SYSTEM_PROCESSOR doesn't seem to be correct - instead get it from the compiler a la c_check
-set(ARCH ${CMAKE_SYSTEM_PROCESSOR} CACHE STRING "Target Architecture")
-
-if (${ARCH} STREQUAL "AMD64")
+if (X86_64)
   set(ARCH "x86_64")
+elseif(X86)
+  set(ARCH "x86")
+elseif(PPC)
+  set(ARCH "power")
+elseif(ARM)
+  set(ARCH "arm")
+elseif(ARM64)
+  set(ARCH "arm64")
+else()
+  set(ARCH ${CMAKE_SYSTEM_PROCESSOR} CACHE STRING "Target Architecture")
 endif ()
 
-# If you are using a 32-bit compiler on a 64-bit system CMAKE_SYSTEM_PROCESSOR will be wrong
-if (${ARCH} STREQUAL "x86_64" AND BINARY EQUAL 32)
-  set(ARCH x86)
-endif ()
+if (NOT BINARY)
+  if (X86_64 OR ARM64 OR PPC OR ARCH STREQUAL "mips64")
+    set(BINARY 64)
+  else ()
+    set(BINARY 32)
+  endif ()
+endif()
 
-if (${ARCH} STREQUAL "X86")
-  set(ARCH x86)
-endif ()
-
-if (${ARCH} MATCHES "ppc")
-  set(ARCH power)
-endif ()
+if(BINARY EQUAL 64)
+  set(BINARY64 1)
+else()
+  set(BINARY32 1)
+endif()
 
 set(COMPILER_ID ${CMAKE_CXX_COMPILER_ID})
 if (${COMPILER_ID} STREQUAL "GNU")
diff --git a/cmake/os.cmake b/cmake/os.cmake
index e9df68d7f..1e9458ccf 100644
--- a/cmake/os.cmake
+++ b/cmake/os.cmake
@@ -78,7 +78,7 @@ if (CYGWIN)
 endif ()
 
 if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows" AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Interix" AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Android")
-  if (SMP)
+  if (USE_THREAD)
     set(EXTRALIB "${EXTRALIB} -lpthread")
   endif ()
 endif ()
diff --git a/cmake/system.cmake b/cmake/system.cmake
index 5fe9081ac..c0957c715 100644
--- a/cmake/system.cmake
+++ b/cmake/system.cmake
@@ -56,11 +56,6 @@ if (CMAKE_BUILD_TYPE STREQUAL "Debug")
   set(GETARCH_FLAGS "${GETARCH_FLAGS} -g")
 endif ()
 
-# TODO: let CMake handle this? -hpa
-#if (${QUIET_MAKE})
-#  set(MAKE "${MAKE} -s")
-#endif()
-
 if (NOT DEFINED NO_PARALLEL_MAKE)
   set(NO_PARALLEL_MAKE 0)
 endif ()
@@ -79,30 +74,18 @@ endif ()
 
 include("${PROJECT_SOURCE_DIR}/cmake/prebuild.cmake")
 
+# N.B. this is NUM_THREAD in Makefile.system which is probably a bug -hpa
 if (NOT DEFINED NUM_THREADS)
   set(NUM_THREADS ${NUM_CORES})
 endif ()
 
 if (${NUM_THREADS} EQUAL 1)
   set(USE_THREAD 0)
+elseif(NOT DEFINED USE_THREAD)
+  set(USE_THREAD 1)
 endif ()
 
-if (DEFINED USE_THREAD)
-  if (NOT ${USE_THREAD})
-    unset(SMP)
-  else ()
-    set(SMP 1)
-  endif ()
-else ()
-  # N.B. this is NUM_THREAD in Makefile.system which is probably a bug -hpa
-  if (${NUM_THREADS} EQUAL 1)
-    unset(SMP)
-  else ()
-    set(SMP 1)
-  endif ()
-endif ()
-
-if (${SMP})
+if (USE_THREAD)
   message(STATUS "SMP enabled.")
 endif ()
 
@@ -182,7 +165,7 @@ if (NO_AVX2)
   set(CCOMMON_OPT "${CCOMMON_OPT} -DNO_AVX2")
 endif ()
 
-if (SMP)
+if (USE_THREAD)
   set(CCOMMON_OPT "${CCOMMON_OPT} -DSMP_SERVER")
 
   if (${ARCH} STREQUAL "mips64")
@@ -386,7 +369,7 @@ if (NOT DEFINED LIBSUFFIX)
 endif ()
 
 if (DYNAMIC_ARCH)
-  if (DEFINED SMP)
+  if (USE_THREAD)
     set(LIBNAME "${LIBPREFIX}p${REVISION}.${LIBSUFFIX}")
     set(LIBNAME_P	"${LIBPREFIX}p${REVISION}_p.${LIBSUFFIX}")
   else ()
@@ -394,7 +377,7 @@ if (DYNAMIC_ARCH)
     set(LIBNAME_P	"${LIBPREFIX}${REVISION}_p.${LIBSUFFIX}")
   endif ()
 else ()
-  if (DEFINED SMP)
+  if (USE_THREAD)
     set(LIBNAME "${LIBPREFIX}_${LIBCORE}p${REVISION}.${LIBSUFFIX}")
     set(LIBNAME_P	"${LIBPREFIX}_${LIBCORE}p${REVISION}_p.${LIBSUFFIX}")
   else ()