diff --git a/cpp/unittest/server/appendix/server_config.yaml b/cpp/unittest/server/appendix/server_config.yaml
index 35e4477d86..b0095b8d37 100644
--- a/cpp/unittest/server/appendix/server_config.yaml
+++ b/cpp/unittest/server/appendix/server_config.yaml
@@ -34,7 +34,6 @@ cache_config:
   gpu_cache_free_percent: 0.85      # old data will be erased from cache when cache is full, this value specify how much memory should be kept, range: greater than zero ~ 1.0
   gpu_ids:                          # gpu id
     - 0
-    - 1
 
 engine_config:
   use_blas_threshold: 20