diff --git a/dev/tests/perftest.lua b/dev/tests/perftest.lua
new file mode 100644
index 00000000..a1cc3cc6
--- /dev/null
+++ b/dev/tests/perftest.lua
@@ -0,0 +1,12 @@
+app.set_setting("chunks.load-distance", 3)
+app.set_setting("chunks.load-speed", 16)
+
+app.reconfig_packs({"base"}, {})
+app.new_world("demo", "2019", "core:default")
+
+local pid = player.create("A")
+assert(player.get_name(pid) == "A")
+app.tick()
+
+timeit(1e7, block.get, 0, 0, 0)
+timeit(1e7, block.set, 0, 0, 0, 6)
diff --git a/doc/en/scripting/builtins/libapp.md b/doc/en/scripting/builtins/libapp.md
index 6b1d8e60..a0a17970 100644
--- a/doc/en/scripting/builtins/libapp.md
+++ b/doc/en/scripting/builtins/libapp.md
@@ -83,6 +83,12 @@ app.reopen_world()
 
 Reopens the world.
 
+```lua
+app.save_world()
+```
+
+Saves the world.
+
 ```lua
 app.close_world(
     -- save the world before closing
diff --git a/doc/ru/scripting/builtins/libapp.md b/doc/ru/scripting/builtins/libapp.md
index 1cf067a2..a30a96e4 100644
--- a/doc/ru/scripting/builtins/libapp.md
+++ b/doc/ru/scripting/builtins/libapp.md
@@ -83,6 +83,12 @@ app.reopen_world()
 
 Переоткрывает мир.
 
+```lua
+app.save_world()
+```
+
+Сохраняет мир.
+
 ```lua
 app.close_world(
     -- сохранить мир перед закрытием
diff --git a/res/scripts/stdlib.lua b/res/scripts/stdlib.lua
index 7900e1c8..714725d0 100644
--- a/res/scripts/stdlib.lua
+++ b/res/scripts/stdlib.lua
@@ -27,6 +27,7 @@ if app then
     app.script = __VC_SCRIPT_NAME
     app.new_world = core.new_world
     app.open_world = core.open_world
+    app.save_world = core.save_world
     app.close_world = core.close_world
     app.reopen_world = core.reopen_world
     app.delete_world = core.delete_world
diff --git a/src/logic/scripting/lua/libs/libcore.cpp b/src/logic/scripting/lua/libs/libcore.cpp
index af15df21..37944694 100644
--- a/src/logic/scripting/lua/libs/libcore.cpp
+++ b/src/logic/scripting/lua/libs/libcore.cpp
@@ -63,6 +63,15 @@ static int l_reopen_world(lua::State*) {
     return 0;
 }
 
+/// @brief Save world
+static int l_save_world(lua::State* L) {
+    if (controller == nullptr) {
+        throw std::runtime_error("no world open");
+    }
+    controller->saveWorld();
+    return 0;
+}
+
 /// @brief Close world
 /// @param flag Save world (bool)
 static int l_close_world(lua::State* L) {
@@ -246,6 +255,7 @@ const luaL_Reg corelib[] = {
     {"new_world", lua::wrap<l_new_world>},
     {"open_world", lua::wrap<l_open_world>},
     {"reopen_world", lua::wrap<l_reopen_world>},
+    {"save_world", lua::wrap<l_save_world>},
     {"close_world", lua::wrap<l_close_world>},
     {"delete_world", lua::wrap<l_delete_world>},
     {"reconfig_packs", lua::wrap<l_reconfig_packs>},
diff --git a/src/voxels/Chunk.hpp b/src/voxels/Chunk.hpp
index 94011d40..55cdac21 100644
--- a/src/voxels/Chunk.hpp
+++ b/src/voxels/Chunk.hpp
@@ -8,6 +8,7 @@
 #include "constants.hpp"
 #include "lighting/Lightmap.hpp"
 #include "util/SmallHeap.hpp"
+#include "maths/aabb.hpp"
 #include "voxel.hpp"
 
 inline constexpr int CHUNK_DATA_LEN = CHUNK_VOL * 4;
@@ -75,4 +76,11 @@ public:
     bool decode(const ubyte* data);
 
     static void convert(ubyte* data, const ContentReport* report);
+
+    AABB getAABB() const {
+        return AABB(
+            glm::vec3(x * CHUNK_W, -INFINITY, z * CHUNK_D),
+            glm::vec3((x + 1) * CHUNK_W, INFINITY, (z + 1) * CHUNK_D)
+        );
+    }
 };
diff --git a/src/voxels/GlobalChunks.cpp b/src/voxels/GlobalChunks.cpp
index a85be528..d82a6b04 100644
--- a/src/voxels/GlobalChunks.cpp
+++ b/src/voxels/GlobalChunks.cpp
@@ -24,6 +24,10 @@ GlobalChunks::GlobalChunks(Level* level)
     chunksMap.max_load_factor(CHUNKS_MAP_MAX_LOAD_FACTOR);
 }
 
+void GlobalChunks::setOnUnload(consumer<Chunk&> onUnload) {
+    this->onUnload = std::move(onUnload);
+}
+
 std::shared_ptr<Chunk> GlobalChunks::fetch(int x, int z) {
     const auto& found = chunksMap.find(keyfrom(x, z));
     if (found == chunksMap.end()) {
@@ -160,6 +164,9 @@ void GlobalChunks::decref(Chunk* chunk) {
         ekey.pos[0] = chunk->x;
         ekey.pos[1] = chunk->z;
 
+        if (onUnload) {
+            onUnload(*chunk);
+        }
         save(chunk);
         chunksMap.erase(ekey.key);
         refCounters.erase(found);
@@ -170,17 +177,11 @@ void GlobalChunks::save(Chunk* chunk) {
     if (chunk == nullptr) {
         return;
     }
-    AABB aabb(
-        glm::vec3(chunk->x * CHUNK_W, -INFINITY, chunk->z * CHUNK_D),
-        glm::vec3(
-            (chunk->x + 1) * CHUNK_W, INFINITY, (chunk->z + 1) * CHUNK_D
-        )
-    );
+    AABB aabb = chunk->getAABB();
     auto entities = level->entities->getAllInside(aabb);
     auto root = dv::object();
     root["data"] = level->entities->serialize(entities);
     if (!entities.empty()) {
-        level->entities->despawn(std::move(entities));
         chunk->flags.entities = true;
     }
     level->getWorld()->wfile->getRegions().put(
diff --git a/src/voxels/GlobalChunks.hpp b/src/voxels/GlobalChunks.hpp
index b4bb45e9..862f6c70 100644
--- a/src/voxels/GlobalChunks.hpp
+++ b/src/voxels/GlobalChunks.hpp
@@ -8,6 +8,7 @@
 #include <glm/gtx/hash.hpp>
 
 #include "voxel.hpp"
+#include "delegates.hpp"
 
 class Chunk;
 class Level;
@@ -30,10 +31,14 @@ class GlobalChunks {
     std::unordered_map<uint64_t, std::shared_ptr<Chunk>> chunksMap;
     std::unordered_map<glm::ivec2, std::shared_ptr<Chunk>> pinnedChunks;
     std::unordered_map<ptrdiff_t, int> refCounters;
+
+    consumer<Chunk&> onUnload;
 public:
     GlobalChunks(Level* level);
     ~GlobalChunks() = default;
 
+    void setOnUnload(consumer<Chunk&> onUnload);
+
     std::shared_ptr<Chunk> fetch(int x, int z);
     std::shared_ptr<Chunk> create(int x, int z);
 
diff --git a/src/world/Level.cpp b/src/world/Level.cpp
index 28a8dab5..2276e9aa 100644
--- a/src/world/Level.cpp
+++ b/src/world/Level.cpp
@@ -58,6 +58,10 @@ Level::Level(
     events->listen(LevelEventType::EVT_CHUNK_HIDDEN, [this](LevelEventType, Chunk* chunk) {
         chunks->decref(chunk);
     });
+    chunks->setOnUnload([this](const Chunk& chunk) {
+        AABB aabb = chunk.getAABB();
+        entities->despawn(entities->getAllInside(aabb));
+    });
     inventories = std::make_unique<Inventories>(*this);
 }