diff --git a/Source/Core/DolphinWX/VideoConfigDiag.cpp b/Source/Core/DolphinWX/VideoConfigDiag.cpp
index 2dae88fcde..9743726f7e 100644
--- a/Source/Core/DolphinWX/VideoConfigDiag.cpp
+++ b/Source/Core/DolphinWX/VideoConfigDiag.cpp
@@ -359,10 +359,15 @@ VideoConfigDiag::VideoConfigDiag(wxWindow* parent, const std::string &title, con
 	{
 	const wxString efbscale_choices[] = { _("Auto (Window Size)"), _("Auto (Multiple of 640x528)"),
 		_("1x Native (640x528)"), _("1.5x Native (960x792)"), _("2x Native (1280x1056)"),
-		_("2.5x Native (1600x1320)"), _("3x Native (1920x1584)"), _("4x Native (2560x2112)") };
+		_("2.5x Native (1600x1320)"), _("3x Native (1920x1584)"), _("4x Native (2560x2112)"), _("Custom") };
 
 	wxChoice *const choice_efbscale = CreateChoice(page_enh,
-		vconfig.iEFBScale, wxGetTranslation(internal_res_desc), sizeof(efbscale_choices)/sizeof(*efbscale_choices), efbscale_choices);
+		vconfig.iEFBScale, wxGetTranslation(internal_res_desc), (vconfig.iEFBScale > 7) ?
+		ArraySize(efbscale_choices) : ArraySize(efbscale_choices) - 1, efbscale_choices);
+
+
+	if (vconfig.iEFBScale > 7)
+		choice_efbscale->SetSelection(8);
 
 	szr_enh->Add(new wxStaticText(page_enh, wxID_ANY, _("Internal Resolution:")), 1, wxALIGN_CENTER_VERTICAL, 0);
 	szr_enh->Add(choice_efbscale);
diff --git a/Source/Core/VideoBackends/D3D/Render.cpp b/Source/Core/VideoBackends/D3D/Render.cpp
index 2f077cdbbd..47b3fe372b 100644
--- a/Source/Core/VideoBackends/D3D/Render.cpp
+++ b/Source/Core/VideoBackends/D3D/Render.cpp
@@ -1370,4 +1370,9 @@ void Renderer::SetInterlacingMode()
 	// TODO
 }
 
+int Renderer::GetMaxTextureSize()
+{
+	return DX11::D3D::GetMaxTextureSize();
+}
+
 }  // namespace DX11
diff --git a/Source/Core/VideoBackends/D3D/Render.h b/Source/Core/VideoBackends/D3D/Render.h
index 9448a85e03..99e682d410 100644
--- a/Source/Core/VideoBackends/D3D/Render.h
+++ b/Source/Core/VideoBackends/D3D/Render.h
@@ -49,6 +49,8 @@ public:
 	bool SaveScreenshot(const std::string &filename, const TargetRectangle &rc) override;
 
 	static bool CheckForResize();
+
+	int GetMaxTextureSize() override;
 };
 
 }
diff --git a/Source/Core/VideoBackends/OGL/Render.cpp b/Source/Core/VideoBackends/OGL/Render.cpp
index 912624acd1..052f6c0444 100644
--- a/Source/Core/VideoBackends/OGL/Render.cpp
+++ b/Source/Core/VideoBackends/OGL/Render.cpp
@@ -1904,4 +1904,11 @@ bool Renderer::SaveScreenshot(const std::string &filename, const TargetRectangle
 
 }
 
+int Renderer::GetMaxTextureSize()
+{
+	int max_size;
+	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_size);
+	return max_size;
+}
+
 }
diff --git a/Source/Core/VideoBackends/OGL/Render.h b/Source/Core/VideoBackends/OGL/Render.h
index de51ed3ee7..0c2534b18f 100644
--- a/Source/Core/VideoBackends/OGL/Render.h
+++ b/Source/Core/VideoBackends/OGL/Render.h
@@ -84,6 +84,8 @@ public:
 
 	bool SaveScreenshot(const std::string &filename, const TargetRectangle &rc) override;
 
+	int GetMaxTextureSize() override;
+
 private:
 	void UpdateEFBCache(EFBAccessType type, u32 cacheRectIdx, const EFBRectangle& efbPixelRc, const TargetRectangle& targetPixelRc, const u32* data);
 };
diff --git a/Source/Core/VideoCommon/RenderBase.cpp b/Source/Core/VideoCommon/RenderBase.cpp
index 726efea803..0e5dbba3cf 100644
--- a/Source/Core/VideoCommon/RenderBase.cpp
+++ b/Source/Core/VideoCommon/RenderBase.cpp
@@ -173,48 +173,12 @@ bool Renderer::CalculateTargetSize(unsigned int framebuffer_width, unsigned int
 	// TODO: Ugly. Clean up
 	switch (s_LastEFBScale)
 	{
-		case 2: // 1x
-			efb_scale_numeratorX = efb_scale_numeratorY = 1;
-			efb_scale_denominatorX = efb_scale_denominatorY = 1;
-			break;
-
-		case 3: // 1.5x
-			efb_scale_numeratorX = efb_scale_numeratorY = 3;
-			efb_scale_denominatorX = efb_scale_denominatorY = 2;
-			break;
-
-		case 4: // 2x
-			efb_scale_numeratorX = efb_scale_numeratorY = 2;
-			efb_scale_denominatorX = efb_scale_denominatorY = 1;
-			break;
-
-		case 5: // 2.5x
-			efb_scale_numeratorX = efb_scale_numeratorY = 5;
-			efb_scale_denominatorX = efb_scale_denominatorY = 2;
-			break;
-
-		case 6: // 3x
-			efb_scale_numeratorX = efb_scale_numeratorY = 3;
-			efb_scale_denominatorX = efb_scale_denominatorY = 1;
-			break;
-
-		case 7: // 4x
-			efb_scale_numeratorX = efb_scale_numeratorY = 4;
-			efb_scale_denominatorX = efb_scale_denominatorY = 1;
-			break;
-
-		default: // fractional & integral handled later
-			break;
-	}
-
-	switch (s_LastEFBScale)
-	{
-		case 0: // fractional
-		case 1: // integral
+		case SCALE_AUTO:
+		case SCALE_AUTO_INTEGRAL:
 			newEFBWidth = FramebufferManagerBase::ScaleToVirtualXfbWidth(EFB_WIDTH, framebuffer_width);
 			newEFBHeight = FramebufferManagerBase::ScaleToVirtualXfbHeight(EFB_HEIGHT, framebuffer_height);
 
-			if (s_LastEFBScale == 1)
+			if (s_LastEFBScale == SCALE_AUTO_INTEGRAL)
 			{
 				newEFBWidth = ((newEFBWidth-1) / EFB_WIDTH + 1) * EFB_WIDTH;
 				newEFBHeight = ((newEFBHeight-1) / EFB_HEIGHT + 1) * EFB_HEIGHT;
@@ -225,10 +189,45 @@ bool Renderer::CalculateTargetSize(unsigned int framebuffer_width, unsigned int
 			efb_scale_denominatorY = EFB_HEIGHT;
 			break;
 
+		case SCALE_1X:
+			efb_scale_numeratorX = efb_scale_numeratorY = 1;
+			efb_scale_denominatorX = efb_scale_denominatorY = 1;
+			break;
+
+		case SCALE_1_5X:
+			efb_scale_numeratorX = efb_scale_numeratorY = 3;
+			efb_scale_denominatorX = efb_scale_denominatorY = 2;
+			break;
+
+		case SCALE_2X:
+			efb_scale_numeratorX = efb_scale_numeratorY = 2;
+			efb_scale_denominatorX = efb_scale_denominatorY = 1;
+			break;
+
+		case SCALE_2_5X:
+			efb_scale_numeratorX = efb_scale_numeratorY = 5;
+			efb_scale_denominatorX = efb_scale_denominatorY = 2;
+			break;
+
+		case SCALE_3X:
+		case SCALE_4X:
 		default:
-			CalculateTargetScale(EFB_WIDTH, EFB_HEIGHT, newEFBWidth, newEFBHeight);
+			efb_scale_numeratorX = efb_scale_numeratorY = s_LastEFBScale - 3;
+			efb_scale_denominatorX = efb_scale_denominatorY = 1;
+
+
+			int maxSize;
+			maxSize = GetMaxTextureSize();
+			if ((unsigned)maxSize < EFB_WIDTH * efb_scale_numeratorX / efb_scale_denominatorX)
+			{
+				efb_scale_numeratorX = efb_scale_numeratorY = (maxSize / EFB_WIDTH);
+				efb_scale_denominatorX = efb_scale_denominatorY = 1;
+			}
+
 			break;
 	}
+	if (s_LastEFBScale > SCALE_AUTO_INTEGRAL)
+		CalculateTargetScale(EFB_WIDTH, EFB_HEIGHT, newEFBWidth, newEFBHeight);
 
 	if (newEFBWidth != s_target_width || newEFBHeight != s_target_height)
 	{
diff --git a/Source/Core/VideoCommon/RenderBase.h b/Source/Core/VideoCommon/RenderBase.h
index 2cd2f03356..3646507bb6 100644
--- a/Source/Core/VideoCommon/RenderBase.h
+++ b/Source/Core/VideoCommon/RenderBase.h
@@ -118,11 +118,13 @@ public:
 	static void StorePixelFormat(PEControl::PixelFormat new_format) { prev_efb_format = new_format; }
 
 	PostProcessingShaderImplementation* GetPostProcessor() { return m_post_processor; }
+	// Max height/width
+	virtual int GetMaxTextureSize() = 0;
 
 protected:
 
 	static void CalculateTargetScale(int x, int y, int &scaledX, int &scaledY);
-	static bool CalculateTargetSize(unsigned int framebuffer_width, unsigned int framebuffer_height);
+	bool CalculateTargetSize(unsigned int framebuffer_width, unsigned int framebuffer_height);
 
 	static void CheckFifoRecording();
 	static void RecordVideoMemory();