diff --git a/sc2/ChangeLog b/sc2/ChangeLog
index a61629c20..e9f7f8b2f 100644
--- a/sc2/ChangeLog
+++ b/sc2/ChangeLog
@@ -1,4 +1,6 @@
 Changes towards version 0.7:
+- Thread down-throttling and game sleep when inactive (currently disabled),
+  (bug #1070), from Flandry
 - Internal changes: GOOD_GUY/BAD_GUY ship flags retired - Alex
 - Fixed Melee menu timeout when both sides are Cyborgs (bug #1067) - Alex
 - Fixed AI ship not moving on warp in (bug #648) - Alex
diff --git a/sc2/src/libs/graphics/sdl/sdl_common.c b/sc2/src/libs/graphics/sdl/sdl_common.c
index ba634f3e5..f68357347 100644
--- a/sc2/src/libs/graphics/sdl/sdl_common.c
+++ b/sc2/src/libs/graphics/sdl/sdl_common.c
@@ -56,6 +56,7 @@ TFB_GRAPHICS_BACKEND *graphics_backend = NULL;
 int RenderedFrames = 0;
 
 volatile int QuitPosted = 0;
+volatile int GameActive = 1; // Track the SDL_ACTIVEEVENT state SDL_APPACTIVE
 
 void
 TFB_PreInit (void)
@@ -198,10 +199,19 @@ TFB_ProcessEvents ()
 	{
 		/* Run through the InputEvent filter. */
 		ProcessInputEvent (&Event);
-		/* Handle Graphics events. */
+		/* Handle graphics and exposure events. */
 		switch (Event.type) {
-			case SDL_ACTIVEEVENT:    /* Lose/gain visibility */
-				// TODO
+			case SDL_ACTIVEEVENT:    /* Lose/gain visibility or focus */
+				/* Up to three different state changes can occur in one event. */
+				/* Here, disregard least significant change (mouse focus). */
+#if 0 /* Currently disabled in mainline */
+				// This controls the automatic sleep/pause when minimized.
+				// On small displays (e.g. mobile devices), APPINPUTFOCUS would 
+				//  be an appropriate substitution for APPACTIVE:
+				// if (Event.active.state & SDL_APPINPUTFOCUS)
+				if (Event.active.state & SDL_APPACTIVE)
+					GameActive = Event.active.gain;
+#endif
 				break;
 			case SDL_QUIT:
 				QuitPosted = 1;
diff --git a/sc2/src/libs/inplib.h b/sc2/src/libs/inplib.h
index e7b238773..5669281b7 100644
--- a/sc2/src/libs/inplib.h
+++ b/sc2/src/libs/inplib.h
@@ -37,6 +37,7 @@ extern BYTE LocateMouse (SWORD *px, SWORD *py);
 
 extern volatile int MouseButtonDown;
 extern volatile int QuitPosted;
+extern volatile int GameActive;
 
 /* Functions for dealing with Character Mode */
 
diff --git a/sc2/src/libs/sound/stream.c b/sc2/src/libs/sound/stream.c
index cabe24a07..fde4c4af4 100644
--- a/sc2/src/libs/sound/stream.c
+++ b/sc2/src/libs/sound/stream.c
@@ -495,11 +495,12 @@ int
 StreamDecoderTaskFunc (void *data)
 {
 	Task task = (Task)data;
+	int active_streams;
 	int i;
 	
 	while (!Task_ReadState (task, TASK_EXIT))
 	{
-		TaskSwitch ();
+		active_streams = 0;
 
 		for (i = MUSIC_SOURCE; i < NUM_SOUNDSOURCES; ++i)
 		{
@@ -517,9 +518,17 @@ StreamDecoderTaskFunc (void *data)
 			}
 
 			process_stream (source);
+			active_streams++;
 
 			UnlockMutex (source->stream_mutex);
 		}
+
+		if (active_streams == 0) 
+		{	// Throttle down the thread when there are no active streams
+			SleepThread (ONE_SECOND / 10);
+		}
+		else
+			TaskSwitch ();
 	}
 
 	FinishTask (task);
diff --git a/sc2/src/uqm.c b/sc2/src/uqm.c
index 8172a4d78..068b9a2ad 100644
--- a/sc2/src/uqm.c
+++ b/sc2/src/uqm.c
@@ -433,6 +433,10 @@ main (int argc, char *argv[])
 			SignalStopMainThread ();
 			++i;
 		}
+		else if (!GameActive)
+		{	// Throttle down the main loop when game is inactive
+			SleepThread (ONE_SECOND / 4);
+		}
 
 		TFB_ProcessEvents ();
 		ProcessUtilityKeys ();
diff --git a/sc2/src/uqm/controls.h b/sc2/src/uqm/controls.h
index 27d9a011e..28195adbf 100644
--- a/sc2/src/uqm/controls.h
+++ b/sc2/src/uqm/controls.h
@@ -100,6 +100,7 @@ void SetMenuRepeatDelay (DWORD min, DWORD max, DWORD step, BOOLEAN gestalt);
 void SetDefaultMenuRepeatDelay (void);
 void ResetKeyRepeat (void);
 BOOLEAN PauseGame (void);
+void SleepGame (void);
 BOOLEAN DoConfirmExit (void);
 BOOLEAN WaitAnyButtonOrQuit (BOOLEAN CheckSpecial);
 void WaitForNoInput (SIZE Duration);
diff --git a/sc2/src/uqm/gameinp.c b/sc2/src/uqm/gameinp.c
index 16795fe9f..6b93aac5e 100644
--- a/sc2/src/uqm/gameinp.c
+++ b/sc2/src/uqm/gameinp.c
@@ -228,6 +228,11 @@ UpdateInputState (void)
 	 * UpdateInputState routinely, so we handle pause and exit
 	 * state updates here. */
 
+	// Automatically pause and enter low-activity state while inactive,
+	// for example, window minimized.
+	if (!GameActive)
+		SleepGame ();
+
 	if (GamePaused)
 		PauseGame ();
 
diff --git a/sc2/src/uqm/starcon.c b/sc2/src/uqm/starcon.c
index 8543ce94c..55f00dfc6 100644
--- a/sc2/src/uqm/starcon.c
+++ b/sc2/src/uqm/starcon.c
@@ -106,6 +106,7 @@ SignalStopMainThread (void)
 {
 	GamePaused = FALSE;
 	GLOBAL (CurrentActivity) |= CHECK_ABORT;
+	TaskSwitch ();
 }
 
 void
diff --git a/sc2/src/uqm/util.c b/sc2/src/uqm/util.c
index 0d15724b3..fe221f60a 100644
--- a/sc2/src/uqm/util.c
+++ b/sc2/src/uqm/util.c
@@ -20,9 +20,11 @@
 #include "controls.h"
 #include "util.h"
 #include "setup.h"
+#include "settings.h"
 #include "libs/inplib.h"
 #include "libs/sound/trackplayer.h"
 #include "libs/mathlib.h"
+#include "libs/log.h"
 
 
 void
@@ -250,3 +252,43 @@ WaitAnyButtonOrQuit (BOOLEAN CheckSpecial)
 	return (GLOBAL (CurrentActivity) & CHECK_ABORT) != 0;
 }
 
+// Stops game clock and music thread and minimizes interrupts/cycles
+//  based on value of global GameActive variable
+// See similar sleep state for main thread in uqm.c:main()
+void
+SleepGame (void)
+{
+	if (QuitPosted)
+		return; // Do not sleep the game when already asked to quit
+
+	log_add (log_Debug, "Game is going to sleep");
+
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE &&
+			LOBYTE (GLOBAL (CurrentActivity)) != WON_LAST_BATTLE)
+		SuspendGameClock ();
+	if (CommData.ConversationPhrases && PlayingTrack ())
+		PauseTrack ();
+	PauseMusic ();
+
+	LockMutex (GraphicsLock);
+
+	while (!GameActive && !QuitPosted)
+		SleepThread (ONE_SECOND / 2);
+
+	log_add (log_Debug, "Game is waking up");
+
+	WaitForNoInput (ONE_SECOND / 10);
+	FlushInput ();
+
+	ResumeMusic ();
+
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE &&
+			LOBYTE (GLOBAL (CurrentActivity)) != WON_LAST_BATTLE)
+		ResumeGameClock ();
+	if (CommData.ConversationPhrases && PlayingTrack ())
+		ResumeTrack ();
+
+	UnlockMutex (GraphicsLock);
+
+	TaskSwitch ();
+}