3 files changed, 24 insertions, 1 deletions
diff --git a/source/blender/blenlib/BLI_system.h b/source/blender/blenlib/BLI_system.h
index 93ad0e1e70f..f4c0399e959 100644
--- a/source/blender/blenlib/BLI_system.h
+++ b/source/blender/blenlib/BLI_system.h
@@ -41,6 +41,10 @@ char *BLI_cpu_brand_string(void);
  */
 void BLI_hostname_get(char *buffer, size_t bufsize);
 
+/* Get maximum addressable memory in megabytes. */
+size_t BLI_system_memory_max_in_megabytes(void);
+int BLI_system_memory_max_in_megabytes_int(void);
+
 /* getpid */
 #ifdef WIN32
 #  define BLI_SYSTEM_PID_H <process.h>
diff --git a/source/blender/blenlib/intern/system.c b/source/blender/blenlib/intern/system.c
index d23b45a3937..3348912f02a 100644
--- a/source/blender/blenlib/intern/system.c
+++ b/source/blender/blenlib/intern/system.c
@@ -18,10 +18,12 @@
  * \ingroup bli
  */
 
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include "BLI_utildefines.h"
+#include "BLI_math_base.h"
 #include "BLI_system.h"
 #include "BLI_string.h"
 
@@ -189,3 +191,20 @@ void BLI_hostname_get(char *buffer, size_t bufsize)
   }
 #endif
 }
+
+size_t BLI_system_memory_max_in_megabytes(void)
+{
+  /* Maximum addressable bytes on this platform.
+   *
+   * NOTE: Due to the shift arithmetic this is a half of the memory. */
+  const size_t limit_bytes_half = (((size_t)1) << ((sizeof(size_t) * 8) - 1));
+  /* Convert it to megabytes and return. */
+  return (limit_bytes_half >> 20) * 2;
+}
+
+int BLI_system_memory_max_in_megabytes_int(void)
+{
+  const size_t limit_megabytes = BLI_system_memory_max_in_megabytes();
+  /* NOTE: The result will fit into integer. */
+  return (int)min_zz(limit_megabytes, (size_t)INT_MAX);
+}
diff --git a/source/blender/blenloader/intern/versioning_defaults.c b/source/blender/blenloader/intern/versioning_defaults.c
index 61623a0cade..0e5e37e54a9 100644
--- a/source/blender/blenloader/intern/versioning_defaults.c
+++ b/source/blender/blenloader/intern/versioning_defaults.c
@@ -96,7 +96,7 @@ void BLO_update_defaults_userpref_blend(void)
   /* Only enable tooltips translation by default,
    * without actually enabling translation itself, for now. */
   U.transopts = USER_TR_TOOLTIPS;
-  U.memcachelimit = 4096;
+  U.memcachelimit = min_ii(BLI_system_memory_max_in_megabytes_int() / 2, 4096);
 
   /* Auto perspective. */
   U.uiflag |= USER_AUTOPERSP;