diff --git a/cpp/src/server/ServerConfig.cpp b/cpp/src/server/ServerConfig.cpp
index bb1879e0b4..4a5d0d0931 100644
--- a/cpp/src/server/ServerConfig.cpp
+++ b/cpp/src/server/ServerConfig.cpp
@@ -84,12 +84,12 @@ ServerError ServerConfig::ValidateConfig() const {
 
     size_t gpu_mem = 0;
     ValidationUtil::GetGpuMemory(gpu_index, gpu_mem);
-    if(index_building_threshold >= gpu_mem/3) {
-        std::cout << "Warnning: index_building_threshold is greater than 1/3 of gpu memory, "
-            << "some index type(such as IVFLAT) may cause cuda::bad_alloc() error" << std::endl;
-    } else if(index_building_threshold >= gpu_mem) {
+    if(index_building_threshold >= gpu_mem) {
         std::cout << "Error: index_building_threshold execeed gpu memory" << std::endl;
         return SERVER_INVALID_ARGUMENT;
+    } else if(index_building_threshold >= gpu_mem/3) {
+        std::cout << "Warnning: index_building_threshold is greater than 1/3 of gpu memory, "
+            << "some index type(such as IVFLAT) may cause cuda::bad_alloc() error" << std::endl;
     }
 
     //cache config validation
@@ -103,7 +103,7 @@ ServerError ServerConfig::ValidateConfig() const {
         std::cout << "Warnning: cpu_cache_capacity value is too aggressive" << std::endl;
     }
 
-    if(insert_buffer_size + cache_cap >= total_mem) if(cache_cap >= total_mem) {
+    if(insert_buffer_size + cache_cap >= total_mem) {
         std::cout << "Error: sum of cpu_cache_capacity and insert_buffer_size execeed system memory" << std::endl;
         return SERVER_INVALID_ARGUMENT;
     }