feat: change default param of n_gpu_layers to 20.

LLama/LLamaModel.cs

@@ -53,7 +53,8 @@ namespace LLama
         public SafeLLamaContextHandle NativeHandle => _ctx;
 
         /// <summary>
-        /// Please refer `LLamaParams` to find the meanings of each arg.
+        /// Please refer `LLamaParams` to find the meanings of each arg. Be sure to have set the `n_gpu_layers`, otherwise it will 
+        /// load 20 layers to gpu by default.
         /// </summary>
         /// <param name="model_path">The model file path.</param>
         /// <param name="model_name">The model name.</param>
@@ -159,7 +160,8 @@ namespace LLama
         }
 
         /// <summary>
-        /// 
+        /// Please refer `LLamaParams` to find the meanings of each arg. Be sure to have set the `n_gpu_layers`, otherwise it will 
+        /// load 20 layers to gpu by default.
         /// </summary>
         /// <param name="params">The LLamaModel params</param>
         /// <param name="name">Model name</param>

LLama/LLamaParams.cs

@@ -12,7 +12,7 @@ namespace LLama
         public int n_ctx = 512; // context size
         public int n_batch = 512; // batch size for prompt processing (must be >=32 to use BLAS)
         public int n_keep = 0; // number of tokens to keep from initial prompt
-        public int n_gpu_layers = 0;   // number of layers to store in VRAM
+        public int n_gpu_layers = -1;   // number of layers to store in VRAM
 
         // sampling parameters
         public Dictionary<llama_token, float> logit_bias; // logit bias for specific tokens
@@ -80,7 +80,7 @@ namespace LLama
             this.n_ctx = n_ctx;
             this.n_batch = n_batch;
             this.n_keep = n_keep;
-            this.n_gpu_layers = n_gpu_layers == -1 ? int.MaxValue : n_gpu_layers;
+            this.n_gpu_layers = n_gpu_layers == -1 ? 20 : n_gpu_layers;
 
             if (logit_bias == null)
             {