diff --git a/BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs b/BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs
index b07a466d7d..47d4e8415a 100644
--- a/BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs
+++ b/BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs
@@ -43,9 +43,7 @@ namespace BizHawk.Emulation.Consoles.Sega
         public YM2413 YM2413;
         public SoundMixer SoundMixer;
         public bool IsGameGear = false;
-
         public bool HasYM2413 = false;
-        public int IPeriod = 228;
 
         public int Frame { get; set; }
         private byte Port01 = 0xFF;
@@ -90,6 +88,9 @@ namespace BizHawk.Emulation.Consoles.Sega
                 PSG.StereoPanning = stereoByte;
             }
 
+            if (Options.Contains("AllowOverclock") && Options.Contains("OverclockSafe"))
+                Vdp.IPeriod = 512;
+
             if (Options.Contains("BIOS"))
             {
                 Port3E = 0xF7; // Disable cartridge, enable BIOS rom
@@ -109,8 +110,7 @@ namespace BizHawk.Emulation.Consoles.Sega
             foreach (string option in Options)
             {
                 var args = option.Split('=');
-                if (args[0] == "IPeriod") IPeriod = int.Parse(args[1]);
-                else if (args[0] == "Japan") Region = "Japan";
+                if (args[0] == "Japan") Region = "Japan";
                 else if (args[0] == "PAL") DisplayType = DisplayType.PAL;
             }
 
@@ -202,7 +202,7 @@ namespace BizHawk.Emulation.Consoles.Sega
             if (HasYM2413)
             {
                 writer.Write("FMRegs " );
-                YM2413.opll.reg.SaveAsHex(writer);
+                   YM2413.opll.reg.SaveAsHex(writer);
             }
             writer.WriteLine("[/SMS]");
         }
diff --git a/BizHawk.Emulation/Consoles/Sega/SMS/VDP.cs b/BizHawk.Emulation/Consoles/Sega/SMS/VDP.cs
index 8c7a06d592..0e17b8ac59 100644
--- a/BizHawk.Emulation/Consoles/Sega/SMS/VDP.cs
+++ b/BizHawk.Emulation/Consoles/Sega/SMS/VDP.cs
@@ -32,6 +32,7 @@ namespace BizHawk.Emulation.Consoles.Sega
         public VdpMode VdpMode { get { return mode; } }
         private DisplayType DisplayType = DisplayType.NTSC;
         private Z80A Cpu;
+        public int IPeriod = 228;
 
         public int ScanLine;
         private int FrameHeight = 192;
@@ -345,7 +346,7 @@ namespace BizHawk.Emulation.Consoles.Sega
                 ProcessFrameInterrupt();
                 ProcessLineInterrupt();
 
-                Cpu.ExecuteCycles(228);
+                Cpu.ExecuteCycles(IPeriod);
 
                 if (ScanLine == scanlinesPerFrame - 1)
                     RenderBlankingRegions();
diff --git a/BizHawk.MultiClient/MainForm.cs b/BizHawk.MultiClient/MainForm.cs
index 807fe255ff..afd520cbaf 100644
--- a/BizHawk.MultiClient/MainForm.cs
+++ b/BizHawk.MultiClient/MainForm.cs
@@ -272,13 +272,13 @@ namespace BizHawk.MultiClient
                     Global.Emulator = new SMS();
                     Global.Emulator.Controller = Global.SMSControls;
                     if (Global.Config.SmsEnableFM) game.AddOptions("UseFM");
-                    if (Global.Config.SmsAllowOverlock) game.AddOptions("AllowOverlock");
+                    if (Global.Config.SmsAllowOverlock) game.AddOptions("AllowOverclock");
                     if (Global.Config.SmsForceStereoSeparation) game.AddOptions("ForceStereo");
                     break;
                 case "GG":
                     Global.Emulator = new SMS { IsGameGear = true };
                     Global.Emulator.Controller = Global.SMSControls;
-                    if (Global.Config.SmsAllowOverlock) game.AddOptions("AllowOverlock");
+                    if (Global.Config.SmsAllowOverlock) game.AddOptions("AllowOverclock");
                     break;
                 case "PCE":
                     Global.Emulator = new PCEngine(NecSystemType.TurboGrafx);
diff --git a/BizHawk.MultiClient/output/gamedb.txt b/BizHawk.MultiClient/output/gamedb.txt
index 0c28e07414..cffc37962f 100644
--- a/BizHawk.MultiClient/output/gamedb.txt
+++ b/BizHawk.MultiClient/output/gamedb.txt
@@ -744,14 +744,14 @@ C7A1FDEF	 	Populous	SMS
 C7C906EA	O	Populous (f)	SMS	
 4A9B4ECB	F	Populous (h) (f)	SMS	
 ABD48AD2	 	Poseidon Wars 3-D	SMS		FM
-4077EFD9	 	Power Strike	SMS		FM
-F94616C4	F	Power Strike (h)	SMS		FM
-514E7ABE	O	Power Strike (2x overdump)	SMS		FM
-4CDC0942	F	Power Strike (2x overdump) (h) [A]	SMS		FM
-37DD9196	F	Power Strike (2x overdump) (h) [B]	SMS		FM
-A109A6FE	 	Power Strike II	SMS	
-673C68B8	B	Power Strike II (eight bad bytes)	SMS	
-979263D8	H	Power Strike II [GG2SMS]	SMS	Game Gear Power Strike II by Chris Covell; v1.00
+4077EFD9	 	Power Strike	SMS		FM;OverclockSafe
+F94616C4	F	Power Strike (h)	SMS		FM;OverclockSafe
+514E7ABE	O	Power Strike (2x overdump)	SMS		FM;OverclockSafe
+4CDC0942	F	Power Strike (2x overdump) (h) [A]	SMS		FM;OverclockSafe
+37DD9196	F	Power Strike (2x overdump) (h) [B]	SMS		FM;OverclockSafe
+A109A6FE	 	Power Strike II	SMS		OverclockSafe
+673C68B8	B	Power Strike II (eight bad bytes)	SMS		OverclockSafe
+979263D8	H	Power Strike II [GG2SMS]	SMS	Game Gear Power Strike II by Chris Covell; v1.00	OverclockSafe
 0047B615	 	Predator 2	SMS	
 518D8547	V	Predator 2 (bad - 42KB missing)	SMS	
 E5F789B9	 	Predator 2 [SMS-GG]	SMS	
@@ -839,7 +839,7 @@ C7F3DA07	H	Rodrigo 2 em - Mate o Papai Noel - Versao de Natal	SMS	Teddy Boy
 947DB11A	H	Rodrigo O Resgate [B]	SMS	Wonder Boy
 715E4E4C	O	Rodrigo O Resgate [B] (6416 bytes oversize)	SMS	
 583A6390	D	Rope Jump	SMS	Peder Johansen
-BB54B6B0	 	R-Type	SMS		FM
+BB54B6B0	 	R-Type	SMS		FM;OverclockSafe
 7510BCE3	T	R-Type (BR) [A]	SMS		FM
 A3C80EE3	T	R-Type (BR) [B]	SMS	Emuboarding emunow.cjb.net	FM
 304D8019	F	R-Type (h)	SMS		FM
@@ -1440,7 +1440,7 @@ CD53F3AF	 	Garfield - Caught in the Act (US)	GG
 A0530664	 	Gear Stadium Heiseiban (JP)	GG	
 E9A2EFB4	 	Gear Works (US)	GG	
 58B44585	 	George Foreman's KO Boxing	GG	
-1B80A75B	 	GG Aleste (JP)	GG	
+1B80A75B	 	GG Aleste (JP)	GG		OverclockSafe
 0EBEA9D4	I	GG BIOS	GG	Found in revision 2 hardware and Majesco Game Gears.
 E2E209C4	D	GG Hicolor Demo v1.00	GG	Chris Covell
 1882C8D7	D	GG Hicolor Demo v1.05	GG	Chris Covell