Index: Src/Model3/Model3.cpp
===================================================================
--- Src/Model3/Model3.cpp	(revision 793)
+++ Src/Model3/Model3.cpp	(working copy)
@@ -2077,7 +2077,7 @@
 
 	// Compute display and VBlank timings
 	unsigned ppcCycles		= m_config["PowerPCFrequency"].ValueAs<unsigned>() * 1000000;
-	unsigned frameCycles	= ppcCycles / 60;
+	unsigned frameCycles	= (uint64_t)ppcCycles * 1000ULL / m_config["RefreshRate"].ValueAs<unsigned>();
 	unsigned gapCycles		= (unsigned)((float)frameCycles * 2.5f / 100.0f);	// we need a gap between asserting irq2 & irq 0x40
 	unsigned offsetCycles = (unsigned)((float)frameCycles * 33.f / 100.0f);
 	unsigned dispCycles		= frameCycles - gapCycles - offsetCycles;
Index: Src/OSD/SDL/Main.cpp
===================================================================
--- Src/OSD/SDL/Main.cpp	(revision 793)
+++ Src/OSD/SDL/Main.cpp	(working copy)
@@ -810,16 +810,37 @@
   SDL_GL_SwapWindow(s_window);
 }
 
-static void SuperSleep(UINT32 time)
+static uint64_t perfctrFreq = 0;
+static uint64_t perfctrStep;
+
+static uint64_t SuperGetTime(void)
 {
-  UINT32 start = SDL_GetTicks();
-  UINT32 tics  = start;
+  return SDL_GetPerformanceCounter();
+}
 
-  while (start + time > tics) {
-    tics = SDL_GetTicks();
+static void SuperSleepUntil(uint64_t tgt)
+{
+  // If we're ahead of the target, we're done.
+  if (SuperGetTime() > tgt) {
+    return;
   }
+
+  int64_t whole = (tgt - SuperGetTime()) * 1000 / perfctrFreq;
+  whole--; // OS sleep isn't accurate, so give an extra millisecond of spinloop
+
+  // Use OS's sleep for whole milliseconds
+  if (whole > 0) {
+    SDL_Delay(whole);
 }
 
+  // Spin until requested time
+  uint64_t now;
+  do {
+    now = SuperGetTime();
+  } while (now < tgt);
+}
+
+
 /******************************************************************************
  Main Program Loop
 ******************************************************************************/
@@ -839,6 +860,7 @@
   bool        quit = false;
   bool        paused = false;
   bool        dumpTimings = false;
+  uint64_t    nextTime;
 
   // Initialize and load ROMs
   if (OKAY != Model3->Init())
@@ -927,10 +949,11 @@
     quit = true;
   }
 #endif
+  perfctrFreq = SDL_GetPerformanceFrequency();
+  perfctrStep = perfctrFreq * 1000 / s_runtime_config["RefreshRate"].ValueAs<unsigned>();
+  nextTime = 0;
   while (!quit)
   {
-    auto startTime = SDL_GetTicks();
-
     // Render if paused, otherwise run a frame
     if (paused)
       Model3->RenderFrame();
@@ -1192,6 +1215,12 @@
     }
 #endif // SUPERMODEL_DEBUGGER
     
+    // Throttle to appropriate speed
+    if (paused || s_runtime_config["Throttle"].ValueAs<bool>())
+    {
+        SuperSleepUntil(nextTime);
+        nextTime = SuperGetTime() + perfctrStep;
+    }
     
     // Frame rate and limiting
     unsigned currentFPSTicks = SDL_GetTicks();
@@ -1198,9 +1227,9 @@
     if (s_runtime_config["ShowFrameRate"].ValueAs<bool>())
     {
       ++fpsFramesElapsed;
-      if((currentFPSTicks-prevFPSTicks) >= 1000)  // update FPS every 1 second (each tick is 1 ms)
+      if((currentFPSTicks-prevFPSTicks) >= 1000)  // update FPS every 1 second (each tick is ~1 ms)
       {
-        sprintf(titleStr, "%s - %1.1f FPS%s", baseTitleStr, (float)fpsFramesElapsed/((float)(currentFPSTicks-prevFPSTicks)/1000.0f), paused ? " (Paused)" : "");
+        sprintf(titleStr, "%s - %1.2f FPS%s", baseTitleStr, (float)fpsFramesElapsed/((float)(currentFPSTicks-prevFPSTicks)/1000.0f), paused ? " (Paused)" : "");
         SDL_SetWindowTitle(s_window, titleStr);
         prevFPSTicks = currentFPSTicks;     // reset tick count
         fpsFramesElapsed = 0;         // reset frame count
@@ -1207,17 +1236,6 @@
       }
     }
     
-    if (paused || s_runtime_config["Throttle"].ValueAs<bool>())
-    {
-        UINT32 endTime    = SDL_GetTicks();
-        UINT32 diff     = endTime - startTime;
-        UINT32 frameTime  = (UINT32)(1000 / 60.f);    // 60 fps, we could roll with 57.5? that would be a jerk fest on 60hz screens though
-
-        if (diff < frameTime) {
-            SuperSleep(frameTime - diff);
-        }
-    }
-
     if (dumpTimings && !paused)
     {
       CModel3 *M = dynamic_cast<CModel3 *>(Model3);
@@ -1384,6 +1402,7 @@
   config.Set("QuadRendering", false);
   config.Set("XResolution", "496");
   config.Set("YResolution", "384");
+  config.Set("RefreshRate", "57524");
   config.Set("FullScreen", false);
   config.Set("WideScreen", false);
   config.Set("Stretch", false);
@@ -1446,10 +1465,11 @@
   puts("  -fullscreen             Full screen mode");
   puts("  -wide-screen            Expand 3D field of view to screen width");
   puts("  -stretch                Fit viewport to resolution, ignoring aspect ratio");
-  puts("  -no-throttle            Disable 60 Hz frame rate lock");
-  puts("  -vsync                  Lock to vertical refresh rate [Default]");
-  puts("  -no-vsync               Do not lock to vertical refresh rate");
-  puts("  -show-fps               Display frame rate in window title bar");
+  puts("  -no-throttle            Disable frame rate lock");
+  puts("  -vsync                  Lock to display's vertical refresh rate [Default]");
+  puts("  -no-vsync               Do not lock to display's vertical refresh rate");
+  printf("  -refresh-rate=<freq>    Set emulated vertical refresh rate in mHz (millihertz) [Default: %d]\n", defaultConfig["RefreshRate"].ValueAs<unsigned>());
+  puts("  -show-fps               Display emulated frame rate in window title bar");
   puts("  -crosshairs=<n>         Crosshairs configuration for gun games:");
   puts("                           0=none [Default], 1=P1 only, 2=P2 only, 3=P1 & P2");
   puts("  -new3d                  New 3D engine by Ian Curtis [Default]");
@@ -1530,6 +1550,7 @@
     { "-frag-shader-fog",       "FragmentShaderFog"       },
     { "-vert-shader-2d",        "VertexShader2D"          },
     { "-frag-shader-2d",        "FragmentShader2D"        },
+    { "-refresh-rate",          "RefreshRate"             },
     { "-sound-volume",          "SoundVolume"             },
     { "-music-volume",          "MusicVolume"             },
     { "-balance",               "Balance"                 },