diff --git a/llama.cpp b/llama.cpp
index a65026122..bfff91be1 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -5658,7 +5658,18 @@ static void llama_model_quantize_internal(const std::string & fname_inp, const s
         nthread = std::thread::hardware_concurrency();
     }
 
-    std::unique_ptr<llama_model_loader> ml(new llama_model_loader(fname_inp, /*use_mmap*/ false));
+    // mmap consistently increases speed Linux, is inconsistent on macOS
+    // (possibly related to free memory), and has not been tested on Windows.
+#ifdef __linux__
+    constexpr bool use_mmap = true;
+#else
+    constexpr bool use_mmap = false;
+#endif
+
+    std::unique_ptr<llama_model_loader> ml(new llama_model_loader(fname_inp, use_mmap));
+    if (ml->use_mmap) {
+        ml->mapping.reset(new llama_mmap(&ml->file, /* prefetch */ 0, ggml_is_numa()));
+    }
 
     llama_model model;
     llm_load_arch(*ml, model);
@@ -5736,10 +5747,12 @@ static void llama_model_quantize_internal(const std::string & fname_inp, const s
 
         const std::string name = ggml_get_name(tensor);
 
-        if (read_data.size() < ggml_nbytes(tensor)) {
-            read_data.resize(ggml_nbytes(tensor));
+        if (!ml->use_mmap) {
+            if (read_data.size() < ggml_nbytes(tensor)) {
+                read_data.resize(ggml_nbytes(tensor));
+            }
+            tensor->data = read_data.data();
         }
-        tensor->data = read_data.data();
         ml->load_data_for(tensor);
 
         LLAMA_LOG_INFO("[%4d/%4d] %36s - [%s], type = %6s, ",