diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index 0f4e480123c7f01d214a1d322c11d000135611e7..b9241a5e0fc28271cc941b57a2d9740f96b1080b 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -18,6 +18,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-152 - Delete assert in MySQLMetaImpl and change MySQLConnectionPool impl
 
 ## New Feature
+- MS-195 - Add nlist and use_blas_threshold conf
 
 ## Task
 
diff --git a/cpp/conf/server_config.template b/cpp/conf/server_config.template
index 0383e00b53daf4c773c3534d3f7aca89d2990559..c7eb134f0d38b7c842e4f011536019ad29f517ee 100644
--- a/cpp/conf/server_config.template
+++ b/cpp/conf/server_config.template
@@ -33,4 +33,6 @@ cache_config:           # cache configure
   cpu_cache_capacity: 16   # how many memory are used as cache, unit: GB, range: 0 ~ less than total memory
 
 engine_config:
-  nprobe: 10
\ No newline at end of file
+  nprobe: 10
+  nlist: 16381
+  use_blas_threshold: 10
\ No newline at end of file
diff --git a/cpp/src/db/FaissExecutionEngine.cpp b/cpp/src/db/FaissExecutionEngine.cpp
index 20bd530e78c9dc230e36e1d830abe1832d13b900..a24c8de25d807b01160c93de436c1d299ac09616 100644
--- a/cpp/src/db/FaissExecutionEngine.cpp
+++ b/cpp/src/db/FaissExecutionEngine.cpp
@@ -167,6 +167,7 @@ Status FaissExecutionEngine::Init() {
         ServerConfig &config = ServerConfig::GetInstance();
         ConfigNode engine_config = config.GetConfig(CONFIG_ENGINE);
         nprobe_ = engine_config.GetInt32Value(CONFIG_NPROBE, 1000);
+        nlist_ = engine_config.GetInt32Value(CONFIG_NLIST,16384);
 
     } else if(build_index_type_ == "IDMap") {
         ;
diff --git a/cpp/src/db/FaissExecutionEngine.h b/cpp/src/db/FaissExecutionEngine.h
index f9f37ad978e0a5c5ddb8affe3057f25bd081ad97..eda0e4d70e45eb3f1e75e174f7ece8d38b2c6fa8 100644
--- a/cpp/src/db/FaissExecutionEngine.h
+++ b/cpp/src/db/FaissExecutionEngine.h
@@ -65,6 +65,7 @@ protected:
     std::string raw_index_type_;
 
     size_t nprobe_ = 0;
+    size_t nlist_ = 0;
 };
 
 
diff --git a/cpp/src/server/MilvusServer.cpp b/cpp/src/server/MilvusServer.cpp
index 452ee3af88b7e429bd11833087d635bbf4012531..ae0664009cf562a1b0c10a25e5ad97c91883a074 100644
--- a/cpp/src/server/MilvusServer.cpp
+++ b/cpp/src/server/MilvusServer.cpp
@@ -11,6 +11,7 @@
 
 #include "milvus_types.h"
 #include "milvus_constants.h"
+#include "faiss/utils.h"
 
 #include <thrift/protocol/TBinaryProtocol.h>
 #include <thrift/protocol/TJSONProtocol.h>
@@ -25,6 +26,8 @@
 #include <thread>
 #include <iostream>
 
+//extern int distance_compute_blas_threshold;
+
 namespace zilliz {
 namespace milvus {
 namespace server {
@@ -46,11 +49,12 @@ MilvusServer::StartService() {
 
     ServerConfig &config = ServerConfig::GetInstance();
     ConfigNode server_config = config.GetConfig(CONFIG_SERVER);
-
+    ConfigNode engine_config = config.GetConfig(CONFIG_ENGINE);
     std::string address = server_config.GetValue(CONFIG_SERVER_ADDRESS, "127.0.0.1");
     int32_t port = server_config.GetInt32Value(CONFIG_SERVER_PORT, 19530);
     std::string protocol = server_config.GetValue(CONFIG_SERVER_PROTOCOL, "binary");
-
+    faiss::distance_compute_blas_threshold = engine_config.GetInt32Value(CONFIG_DCBT,20);
+//    std::cout<<"distance_compute_blas_threshold = "<< faiss::distance_compute_blas_threshold << std::endl;
     try {
         DBWrapper::DB();//initialize db
 
diff --git a/cpp/src/server/ServerConfig.h b/cpp/src/server/ServerConfig.h
index 0ec04eed8c935ae1e30652ea71ec2788f96e81bb..c5565b7282b4d87714040620837af690658225c1 100644
--- a/cpp/src/server/ServerConfig.h
+++ b/cpp/src/server/ServerConfig.h
@@ -44,6 +44,8 @@ static const std::string CONFIG_METRIC_PROMETHEUS_PORT = "port";
 
 static const std::string CONFIG_ENGINE = "engine_config";
 static const std::string CONFIG_NPROBE = "nprobe";
+static const std::string CONFIG_NLIST = "nlist";
+static const std::string CONFIG_DCBT = "use_blas_threshold";
 
 class ServerConfig {
  public:
diff --git a/cpp/src/wrapper/Operand.cpp b/cpp/src/wrapper/Operand.cpp
index 25341676a67fd2ceebdef5f1a421a06b22f8d290..0d526198ad6fb895c1eb33078d66102e0b0e3fb9 100644
--- a/cpp/src/wrapper/Operand.cpp
+++ b/cpp/src/wrapper/Operand.cpp
@@ -4,6 +4,7 @@
 // Proprietary and confidential.
 ////////////////////////////////////////////////////////////////////////////////
 
+#include "src/server/ServerConfig.h"
 #include "Operand.h"
 
 
@@ -38,8 +39,15 @@ string Operand::get_index_type(const int &nb) {
             break;
         }
         case IVF: {
+
+            using namespace zilliz::milvus::server;
+            ServerConfig &config = ServerConfig::GetInstance();
+            ConfigNode engine_config = config.GetConfig(CONFIG_ENGINE);
+            size_t nlist = engine_config.GetInt32Value(CONFIG_NLIST, 16384);
+
             index_str += (ncent != 0 ? index_type + std::to_string(ncent) :
-                          index_type + std::to_string(int(nb / 1000000.0 * 16384)));
+                          index_type + std::to_string(int(nb / 1000000.0 * nlist)));
+//            std::cout<<"nlist = "<<nlist<<std::endl;
             break;
         }
         case IDMAP: {