diff --git a/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.cpp b/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.cpp
index 7b09a588f8..d09ba76d2c 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.cpp
+++ b/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.cpp
@@ -49,11 +49,12 @@ static int cur_adapter;
 
 // Value caches for state filtering
 const int MaxTextureStages = 9;
-const int MaxRenderStates = 210;
-const DWORD MaxTextureTypes = 33;
-const DWORD MaxSamplerSize = 13;
-const DWORD MaxSamplerTypes = 15;
-static DWORD m_RenderStates[MaxRenderStates+46];
+const int MaxRenderStates = 210 + 46;
+const int MaxTextureTypes = 33;
+const int MaxSamplerSize = 13;
+const int MaxSamplerTypes = 15;
+static bool m_RenderStatesSet[MaxRenderStates];
+static DWORD m_RenderStates[MaxRenderStates];
 static DWORD m_TextureStageStates[MaxTextureStages][MaxTextureTypes];
 static DWORD m_SamplerStates[MaxSamplerSize][MaxSamplerTypes];
 LPDIRECT3DBASETEXTURE9 m_Textures[16];
@@ -185,6 +186,24 @@ void Enumerate()
 				}
 			}
 		}
+
+		// Determine if INTZ is supported. Code from ATI's doc.
+		// http://developer.amd.com/gpu_assets/Advanced%20DX9%20Capabilities%20for%20ATI%20Radeon%20Cards.pdf
+		a.supports_intz = D3D_OK == D3D->CheckDeviceFormat(
+			i, D3DDEVTYPE_HAL, D3DFMT_X8R8G8B8,
+			D3DUSAGE_DEPTHSTENCIL, D3DRTYPE_TEXTURE, FOURCC_INTZ); 
+		// Also check for RAWZ (nvidia only, but the only option to get Z24 textures on sub GF8800
+		a.supports_rawz = D3D_OK == D3D->CheckDeviceFormat(
+			i, D3DDEVTYPE_HAL, D3DFMT_X8R8G8B8,
+			D3DUSAGE_DEPTHSTENCIL, D3DRTYPE_TEXTURE, FOURCC_RAWZ); 
+		// Might as well check for RESZ and NULL too.
+		a.supports_resz = D3D_OK == D3D->CheckDeviceFormat(
+			i, D3DDEVTYPE_HAL, D3DFMT_X8R8G8B8,
+			D3DUSAGE_DEPTHSTENCIL, D3DRTYPE_TEXTURE, FOURCC_RESZ); 
+		a.supports_resz = D3D_OK == D3D->CheckDeviceFormat(
+			i, D3DDEVTYPE_HAL, D3DFMT_X8R8G8B8,
+			D3DUSAGE_DEPTHSTENCIL, D3DRTYPE_TEXTURE, FOURCC_NULL); 
+
 		if (a.aa_levels.size() == 1)
 		{
 			strcpy(a.aa_levels[0].name, "(Not supported on this device)");
@@ -260,6 +279,7 @@ HRESULT Create(int adapter, HWND wnd, bool _fullscreen, int _resolution, int aa_
 			return E_FAIL;
 		}
 	}
+
 	dev->GetDeviceCaps(&caps);
 	dev->GetRenderTarget(0, &back_buffer);
 	if (dev->GetDepthStencilSurface(&back_buffer_z) == D3DERR_NOTFOUND)
@@ -322,7 +342,7 @@ void Reset()
 {
 	if (dev)
 	{
-		ForgetCachedState();
+		// ForgetCachedState();
 
 		// Can't keep a pointer around to the backbuffer surface when resetting.
 		if (back_buffer_z)
@@ -339,6 +359,7 @@ void Reset()
 		dev->GetRenderTarget(0, &back_buffer);
 		if (dev->GetDepthStencilSurface(&back_buffer_z) == D3DERR_NOTFOUND)
 			back_buffer_z = NULL;
+		ApplyCachedState();
 	}
 }
 
@@ -401,12 +422,26 @@ void EndFrame()
 	}
 }
 
-void ForgetCachedState()
+void ApplyCachedState()
 {
+	for (int sampler = 0; sampler < 8; sampler++)
+	{
+		for (int type = 0; type < MaxSamplerTypes; type++)
+		{
+			D3D::dev->SetSamplerState(sampler, (D3DSAMPLERSTATETYPE)type, m_SamplerStates[sampler][type]);
+		}
+	}
+
+	for (int rs = 0; rs < MaxRenderStates; rs++)
+	{
+		if (m_RenderStatesSet[rs])
+			D3D::dev->SetRenderState((D3DRENDERSTATETYPE)rs, m_RenderStates[rs]);
+	}
+
+	// We don't bother restoring these so let's just wipe the state copy
+	// so no stale state is around.
 	memset(m_Textures, 0, sizeof(m_Textures));
-	memset(m_RenderStates, 0xFF, sizeof(m_RenderStates));
 	memset(m_TextureStageStates, 0xFF, sizeof(m_TextureStageStates));
-	memset(m_SamplerStates, 0xFF, sizeof(m_SamplerStates));
 }
 
 void SetTexture(DWORD Stage, LPDIRECT3DBASETEXTURE9 pTexture)
@@ -423,6 +458,7 @@ void SetRenderState(D3DRENDERSTATETYPE State, DWORD Value)
 	if (m_RenderStates[State] != Value)
 	{
 		m_RenderStates[State] = Value;
+		m_RenderStatesSet[State] = true;
 		D3D::dev->SetRenderState(State, Value);
 	}
 }
diff --git a/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.h b/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.h
index c92168a9cf..f7c4b80bba 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.h
+++ b/Source/Plugins/Plugin_VideoDX9/Src/D3DBase.h
@@ -28,6 +28,20 @@
 namespace D3D
 {
 
+// From http://developer.amd.com/gpu_assets/Advanced%20DX9%20Capabilities%20for%20ATI%20Radeon%20Cards.pdf
+// Magic FourCC's to unlock undocumented D3D9 features:
+
+// Z texture formats
+#define FOURCC_INTZ ((D3DFORMAT)(MAKEFOURCC('I','N','T','Z')))
+#define FOURCC_RAWZ ((D3DFORMAT)(MAKEFOURCC('R','A','W','Z')))
+
+// Depth buffer resolve:
+#define FOURCC_RESZ ((D3DFORMAT)(MAKEFOURCC('R','E','S','Z')))
+#define RESZ_CODE 0x7fa05000
+
+// Null render target to do Z-only shadow maps: (probably not useful for Dolphin)
+#define FOURCC_NULL ((D3DFORMAT)(MAKEFOURCC('N','U','L','L')))
+
 HRESULT Init();
 HRESULT Create(int adapter, HWND wnd, bool fullscreen, int resolution, int aa_mode, bool auto_depth);
 void Close();
@@ -41,6 +55,7 @@ bool BeginFrame();
 void EndFrame();
 void SwitchFullscreen(bool fullscreen);
 bool IsFullscreen();
+bool CanUseINTZ();
 
 int GetBackBufferWidth();
 int GetBackBufferHeight();
@@ -57,7 +72,7 @@ void SetTexture(DWORD Stage, IDirect3DBaseTexture9 *pTexture);
 void SetRenderState(D3DRENDERSTATETYPE State, DWORD Value);
 void SetTextureStageState(DWORD Stage, D3DTEXTURESTAGESTATETYPE Type, DWORD Value);
 void SetSamplerState(DWORD Sampler, D3DSAMPLERSTATETYPE Type, DWORD Value);
-void ForgetCachedState();
+void ApplyCachedState();
 
 // Utility functions for vendor specific hacks. So far, just the one.
 void EnableAlphaToCoverage();
@@ -85,6 +100,12 @@ struct Adapter
 	std::vector<Resolution> resolutions;
 	std::vector<AALevel> aa_levels;
 	bool supports_alpha_to_coverage;
+
+	// Magic render targets, see the top of this file.
+	bool supports_intz;
+	bool supports_rawz;
+	bool supports_resz;
+	bool supports_null;
 };
 
 const Adapter &GetAdapter(int i);