diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index 4822bcb16b1dabc066d8ff5b50b0d333f9468a9b..563164d458143a8950731e8d2f2da3fdbaa3e9f3 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -23,6 +23,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-65 - Implement GetTableRowCount interface
 - MS-45 - Implement DeleteTable interface
 - MS-75 - cmake: change faiss version to 1.5.2; add CUDA gencode
+- MS-81 - fix faiss ptx issue; change cuda gencode
 
 ## Task
 - MS-74 - Change README.md in cpp
diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index 194fdf7e1e7c0602b440d9bfb94c2c3d2e04c09e..028b602056bd17cee66f2f84358f03e8de2f8b47 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -44,33 +44,6 @@ if("${MAKE}" STREQUAL "")
     endif()
 endif()
 
-set(GCC_VERSION 5.3.0)
-set(GCC_DIR "${CMAKE_CURRENT_BINARY_DIR}/gcc")
-set(GCC_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/gcc/gcc_build")
-set(GCC_TAR_NAME "${GCC_BUILD_DIR}/gcc-${GCC_VERSION}.tar.gz")
-if (NOT EXISTS ${GCC_TAR_NAME})
-    file(MAKE_DIRECTORY ${GCC_BUILD_DIR})
-    file(DOWNLOAD http://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-${GCC_VERSION}/${GCC_TAR_NAME}
-            ${GCC_TAR_NAME})
-    message(STATUS "Building GCC-${GCC_VERSION} from source")
-    execute_process(
-            COMMAND
-            "${CMAKE_COMMAND} -E tar -xf ${GCC_TAR_NAME}"
-            COMMAND
-            "./configure --prefix=${GCC_DIR} --with-local-prefix=${GCC_DIR}
-            --enable-languages=cxx,fortran
-            --enable-checking=release
-            --disable-bootstrap"
-            COMMAND
-            "${MAKE} -j4"
-            COMMAND
-            "${MAKE} install"
-            RESULT_VARIABLE	_status
-            #OUTPUT_QUIET
-            #ERROR_QUIET
-            WORKING_DIRECTORY ${GCC_BUILD_DIR})
-endif ()
-
 set(MEGASEARCH_VERSION_MAJOR "${megasearch_VERSION_MAJOR}")
 set(MEGASEARCH_VERSION_MINOR "${megasearch_VERSION_MINOR}")
 set(MEGASEARCH_VERSION_PATCH "${megasearch_VERSION_PATCH}")
diff --git a/cpp/cmake/DefineOptions.cmake b/cpp/cmake/DefineOptions.cmake
index 340e72d8477254ab8f70ac0d9ef0c9b34a2d94bd..538e54fe3b0efde721727057aa197c2318299cc2 100644
--- a/cpp/cmake/DefineOptions.cmake
+++ b/cpp/cmake/DefineOptions.cmake
@@ -70,8 +70,8 @@ define_option(MEGASEARCH_WITH_FAISS "Build with FAISS library" ON)
 
 define_option(MEGASEARCH_WITH_FAISS_GPU_VERSION "Build with FAISS GPU version" ON)
 
-define_option_string(MEGASEARCH_FAISS_GPU_ARCH "Specifying which GPU architectures to build against"
-        "-gencode=arch=compute_35,code=sm_35 -gencode=arch=compute_52,code=sm_52 -gencode=arch=compute_60,code=sm_60 -gencode=arch=compute_61,code=sm_61")
+#define_option_string(MEGASEARCH_FAISS_GPU_ARCH "Specifying which GPU architectures to build against"
+#        "-gencode=arch=compute_35,code=compute_35 -gencode=arch=compute_52,code=compute_52 -gencode=arch=compute_60,code=compute_60 -gencode=arch=compute_61,code=compute_61")
 
 define_option(MEGASEARCH_WITH_LAPACK "Build with LAPACK library" ON)
 
diff --git a/cpp/cmake/ThirdPartyPackages.cmake b/cpp/cmake/ThirdPartyPackages.cmake
index bdb573ca7d86c321558d049808ab15124bfe680d..ca84bca7b070136588e867c5361b20b05cc6f2d3 100644
--- a/cpp/cmake/ThirdPartyPackages.cmake
+++ b/cpp/cmake/ThirdPartyPackages.cmake
@@ -686,7 +686,15 @@ macro(build_faiss)
     if(${MEGASEARCH_WITH_FAISS_GPU_VERSION} STREQUAL "ON")
         set(FAISS_CONFIGURE_ARGS ${FAISS_CONFIGURE_ARGS}
                 "--with-cuda=${CUDA_TOOLKIT_ROOT_DIR}"
-                "--with-cuda-arch=${MEGASEARCH_FAISS_GPU_ARCH}")
+#                "with_cuda_arch=\"-gencode=arch=compute_35,code=compute_35 \\
+#                                    -gencode=arch=compute_52,code=compute_52 \\
+#                                    -gencode=arch=compute_60,code=compute_60 \\
+#                                    -gencode=arch=compute_61,code=compute_61\""
+                "--with-cuda-arch=\"-gencode=arch=compute_35,code=compute_35\""
+                "--with-cuda-arch=\"-gencode=arch=compute_52,code=compute_52\""
+                "--with-cuda-arch=\"-gencode=arch=compute_60,code=compute_60\""
+                "--with-cuda-arch=\"-gencode=arch=compute_61,code=compute_61\""
+                )
     else()
         set(FAISS_CONFIGURE_ARGS ${FAISS_CONFIGURE_ARGS} --without-cuda)
     endif()