diff --git a/python/sglang/srt/server_args.py b/python/sglang/srt/server_args.py
index dbfd48efb..b5ae57817 100644
--- a/python/sglang/srt/server_args.py
+++ b/python/sglang/srt/server_args.py
@@ -371,7 +371,7 @@ class ServerArgs:
     # Mamba cache
     max_mamba_cache_size: Optional[int] = None
     mamba_ssm_dtype: str = "float32"
-    mamba_full_memory_ratio: float = 0.2
+    mamba_full_memory_ratio: float = 0.9
 
     # Hierarchical cache
     enable_hierarchical_cache: bool = False