diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt
index 9c6450a751..4765931909 100644
--- a/common/CMakeLists.txt
+++ b/common/CMakeLists.txt
@@ -21,6 +21,7 @@ target_sources(common PRIVATE
 	FileSystem.cpp
 	Image.cpp
 	HTTPDownloader.cpp
+	MemorySettingsInterface.cpp
 	Misc.cpp
 	MD5Digest.cpp
 	PrecompiledHeader.cpp
@@ -72,10 +73,12 @@ target_sources(common PRIVATE
 	FileSystem.h
 	General.h
 	HashCombine.h
+	HeterogeneousContainers.h
 	Image.h
 	LRUCache.h
 	HTTPDownloader.h
 	MemcpyFast.h
+	MemorySettingsInterface.h
 	MemsetFast.inl
 	MD5Digest.h
 	MRCHelpers.h
diff --git a/common/HeterogeneousContainers.h b/common/HeterogeneousContainers.h
new file mode 100644
index 0000000000..f19ec80360
--- /dev/null
+++ b/common/HeterogeneousContainers.h
@@ -0,0 +1,78 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2010  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Provides a map template which doesn't require heap allocations for lookups.
+ */
+
+#pragma once
+
+#include <map>
+#include <set>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+
+namespace detail
+{
+	struct transparent_string_hash
+	{
+		using is_transparent = void;
+
+		std::size_t operator()(const std::string_view& v) const { return std::hash<std::string_view>{}(v); }
+		std::size_t operator()(const std::string& s) const { return std::hash<std::string>{}(s); }
+		std::size_t operator()(const char* s) const { return operator()(std::string_view(s)); }
+	};
+
+	struct transparent_string_equal
+	{
+		using is_transparent = void;
+
+		bool operator()(const std::string& lhs, const std::string_view& rhs) const { return lhs == rhs; }
+		bool operator()(const std::string& lhs, const std::string& rhs) const { return lhs == rhs; }
+		bool operator()(const std::string& lhs, const char* rhs) const { return lhs == rhs; }
+		bool operator()(const std::string_view& lhs, const std::string& rhs) const { return lhs == rhs; }
+		bool operator()(const char* lhs, const std::string& rhs) const { return lhs == rhs; }
+	};
+
+	struct transparent_string_less
+	{
+		using is_transparent = void;
+
+		bool operator()(const std::string& lhs, const std::string_view& rhs) const { return lhs < rhs; }
+		bool operator()(const std::string& lhs, const std::string& rhs) const { return lhs < rhs; }
+		bool operator()(const std::string& lhs, const char* rhs) const { return lhs < rhs; }
+		bool operator()(const std::string_view& lhs, const std::string& rhs) const { return lhs < rhs; }
+		bool operator()(const char* lhs, const std::string& rhs) const { return lhs < rhs; }
+	};
+} // namespace detail
+
+template <typename ValueType>
+using UnorderedStringMap =
+	std::unordered_map<std::string, ValueType, detail::transparent_string_hash, detail::transparent_string_equal>;
+template <typename ValueType>
+using UnorderedStringMultimap =
+	std::unordered_multimap<std::string, ValueType, detail::transparent_string_hash, detail::transparent_string_equal>;
+using UnorderedStringSet =
+	std::unordered_set<std::string, detail::transparent_string_hash, detail::transparent_string_equal>;
+using UnorderedStringMultiSet =
+	std::unordered_multiset<std::string, detail::transparent_string_hash, detail::transparent_string_equal>;
+
+template <typename ValueType>
+using StringMap = std::map<std::string, ValueType, detail::transparent_string_less>;
+template <typename ValueType>
+using StringMultiMap = std::multimap<std::string, ValueType, detail::transparent_string_less>;
+using StringSet = std::set<std::string, detail::transparent_string_less>;
+using StringMultiSet = std::multiset<std::string, detail::transparent_string_less>;
diff --git a/common/MemorySettingsInterface.cpp b/common/MemorySettingsInterface.cpp
new file mode 100644
index 0000000000..8414a49ff5
--- /dev/null
+++ b/common/MemorySettingsInterface.cpp
@@ -0,0 +1,290 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2022  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common/MemorySettingsInterface.h"
+#include "common/StringUtil.h"
+
+MemorySettingsInterface::MemorySettingsInterface() = default;
+
+MemorySettingsInterface::~MemorySettingsInterface() = default;
+
+bool MemorySettingsInterface::Save()
+{
+	return false;
+}
+
+void MemorySettingsInterface::Clear()
+{
+	m_sections.clear();
+}
+
+bool MemorySettingsInterface::GetIntValue(const char* section, const char* key, s32* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	std::optional<s32> parsed = StringUtil::FromChars<s32>(iter->second, 10);
+	if (!parsed.has_value())
+		return false;
+
+	*value = parsed.value();
+	return true;
+}
+
+bool MemorySettingsInterface::GetUIntValue(const char* section, const char* key, u32* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	std::optional<u32> parsed = StringUtil::FromChars<u32>(iter->second, 10);
+	if (!parsed.has_value())
+		return false;
+
+	*value = parsed.value();
+	return true;
+}
+
+bool MemorySettingsInterface::GetFloatValue(const char* section, const char* key, float* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	std::optional<float> parsed = StringUtil::FromChars<float>(iter->second);
+	if (!parsed.has_value())
+		return false;
+
+	*value = parsed.value();
+	return true;
+}
+
+bool MemorySettingsInterface::GetDoubleValue(const char* section, const char* key, double* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	std::optional<double> parsed = StringUtil::FromChars<double>(iter->second);
+	if (!parsed.has_value())
+		return false;
+
+	*value = parsed.value();
+	return true;
+}
+
+bool MemorySettingsInterface::GetBoolValue(const char* section, const char* key, bool* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	std::optional<bool> parsed = StringUtil::FromChars<bool>(iter->second);
+	if (!parsed.has_value())
+		return false;
+
+	*value = parsed.value();
+	return true;
+}
+
+bool MemorySettingsInterface::GetStringValue(const char* section, const char* key, std::string* value) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	const auto iter = sit->second.find(key);
+	if (iter == sit->second.end())
+		return false;
+
+	*value = iter->second;
+	return true;
+}
+
+void MemorySettingsInterface::SetIntValue(const char* section, const char* key, s32 value)
+{
+	SetValue(section, key, std::to_string(value));
+}
+
+void MemorySettingsInterface::SetUIntValue(const char* section, const char* key, u32 value)
+{
+	SetValue(section, key, std::to_string(value));
+}
+
+void MemorySettingsInterface::SetFloatValue(const char* section, const char* key, float value)
+{
+	SetValue(section, key, std::to_string(value));
+}
+
+void MemorySettingsInterface::SetDoubleValue(const char* section, const char* key, double value)
+{
+	SetValue(section, key, std::to_string(value));
+}
+
+void MemorySettingsInterface::SetBoolValue(const char* section, const char* key, bool value)
+{
+	SetValue(section, key, std::to_string(value));
+}
+
+void MemorySettingsInterface::SetStringValue(const char* section, const char* key, const char* value)
+{
+	SetValue(section, key, value);
+}
+
+void MemorySettingsInterface::SetValue(const char* section, const char* key, std::string value)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		sit = m_sections.emplace(std::make_pair(std::string(section), KeyMap())).first;
+
+	const auto range = sit->second.equal_range(key);
+	if (range.first == sit->second.end())
+	{
+		sit->second.emplace(std::string(key), std::move(value));
+		return;
+	}
+
+	auto iter = range.first;
+	iter->second = std::move(value);
+	++iter;
+
+	// remove other values
+	while (iter != range.second)
+	{
+		auto remove = iter++;
+		sit->second.erase(remove);
+	}
+}
+
+std::vector<std::string> MemorySettingsInterface::GetStringList(const char* section, const char* key) const
+{
+	std::vector<std::string> ret;
+
+	const auto sit = m_sections.find(section);
+	if (sit != m_sections.end())
+	{
+		const auto range = sit->second.equal_range(key);
+		for (auto iter = range.first; iter != range.second; ++iter)
+			ret.emplace_back(iter->second);
+	}
+
+	return ret;
+}
+
+void MemorySettingsInterface::SetStringList(const char* section, const char* key, const std::vector<std::string>& items)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		sit = m_sections.emplace(std::make_pair(std::string(section), KeyMap())).first;
+
+	const auto range = sit->second.equal_range(key);
+	for (auto iter = range.first; iter != range.second;)
+		sit->second.erase(iter++);
+
+	std::string_view keysv(key);
+	for (const std::string& value : items)
+		sit->second.emplace(keysv, value);
+}
+
+bool MemorySettingsInterface::RemoveFromStringList(const char* section, const char* key, const char* item)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		sit = m_sections.emplace(std::make_pair(std::string(section), KeyMap())).first;
+
+	const auto range = sit->second.equal_range(key);
+	bool result = false;
+	for (auto iter = range.first; iter != range.second;)
+	{
+		if (iter->second == item)
+		{
+			sit->second.erase(iter++);
+			result = true;
+		}
+		else
+		{
+			++iter;
+		}
+	}
+
+	return result;
+}
+
+bool MemorySettingsInterface::AddToStringList(const char* section, const char* key, const char* item)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		sit = m_sections.emplace(std::make_pair(std::string(section), KeyMap())).first;
+
+	const auto range = sit->second.equal_range(key);
+	for (auto iter = range.first; iter != range.second; ++iter)
+	{
+		if (iter->second == item)
+			return false;
+	}
+
+	sit->second.emplace(std::string(key), std::string(item));
+	return true;
+}
+
+bool MemorySettingsInterface::ContainsValue(const char* section, const char* key) const
+{
+	const auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return false;
+
+	return (sit->second.find(key) != sit->second.end());
+}
+
+void MemorySettingsInterface::DeleteValue(const char* section, const char* key)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return;
+
+	const auto range = sit->second.equal_range(key);
+	for (auto iter = range.first; iter != range.second;)
+		sit->second.erase(iter++);
+}
+
+void MemorySettingsInterface::ClearSection(const char* section)
+{
+	auto sit = m_sections.find(section);
+	if (sit == m_sections.end())
+		return;
+
+	m_sections.erase(sit);
+}
diff --git a/common/MemorySettingsInterface.h b/common/MemorySettingsInterface.h
new file mode 100644
index 0000000000..c1fc1926c1
--- /dev/null
+++ b/common/MemorySettingsInterface.h
@@ -0,0 +1,68 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2022  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include "HeterogeneousContainers.h"
+#include "SettingsInterface.h"
+#include <string>
+
+class MemorySettingsInterface final : public SettingsInterface
+{
+public:
+	MemorySettingsInterface();
+	~MemorySettingsInterface();
+
+	bool Save() override;
+
+	void Clear() override;
+
+	bool GetIntValue(const char* section, const char* key, s32* value) const override;
+	bool GetUIntValue(const char* section, const char* key, u32* value) const override;
+	bool GetFloatValue(const char* section, const char* key, float* value) const override;
+	bool GetDoubleValue(const char* section, const char* key, double* value) const override;
+	bool GetBoolValue(const char* section, const char* key, bool* value) const override;
+	bool GetStringValue(const char* section, const char* key, std::string* value) const override;
+
+	void SetIntValue(const char* section, const char* key, s32 value) override;
+	void SetUIntValue(const char* section, const char* key, u32 value) override;
+	void SetFloatValue(const char* section, const char* key, float value) override;
+	void SetDoubleValue(const char* section, const char* key, double value) override;
+	void SetBoolValue(const char* section, const char* key, bool value) override;
+	void SetStringValue(const char* section, const char* key, const char* value) override;
+	bool ContainsValue(const char* section, const char* key) const override;
+	void DeleteValue(const char* section, const char* key) override;
+	void ClearSection(const char* section) override;
+
+	std::vector<std::string> GetStringList(const char* section, const char* key) const override;
+	void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) override;
+	bool RemoveFromStringList(const char* section, const char* key, const char* item) override;
+	bool AddToStringList(const char* section, const char* key, const char* item) override;
+
+	// default parameter overloads
+	using SettingsInterface::GetBoolValue;
+	using SettingsInterface::GetDoubleValue;
+	using SettingsInterface::GetFloatValue;
+	using SettingsInterface::GetIntValue;
+	using SettingsInterface::GetStringValue;
+	using SettingsInterface::GetUIntValue;
+
+private:
+	using KeyMap = UnorderedStringMultimap<std::string>;
+	using SectionMap = UnorderedStringMap<KeyMap>;
+
+	void SetValue(const char* section, const char* key, std::string value);
+
+	SectionMap m_sections;
+};
\ No newline at end of file
diff --git a/common/common.vcxproj b/common/common.vcxproj
index 418ffbb4d1..1f96255e94 100644
--- a/common/common.vcxproj
+++ b/common/common.vcxproj
@@ -79,6 +79,7 @@
     </ClCompile>
     <ClCompile Include="HTTPDownloaderWinHTTP.cpp" />
     <ClCompile Include="MD5Digest.cpp" />
+    <ClCompile Include="MemorySettingsInterface.cpp" />
     <ClCompile Include="ProgressCallback.cpp" />
     <ClCompile Include="StackWalker.cpp" />
     <ClCompile Include="StringUtil.cpp" />
@@ -151,6 +152,7 @@
     <ClInclude Include="GL\StreamBuffer.h" />
     <ClInclude Include="FileSystem.h" />
     <ClInclude Include="HashCombine.h" />
+    <ClInclude Include="HeterogeneousContainers.h" />
     <ClInclude Include="Image.h" />
     <ClInclude Include="LRUCache.h" />
     <ClInclude Include="HTTPDownloader.h" />
@@ -159,6 +161,7 @@
     </ClInclude>
     <ClInclude Include="HTTPDownloaderWinHTTP.h" />
     <ClInclude Include="MD5Digest.h" />
+    <ClInclude Include="MemorySettingsInterface.h" />
     <ClInclude Include="ProgressCallback.h" />
     <ClInclude Include="ScopedGuard.h" />
     <ClInclude Include="StackWalker.h" />
diff --git a/common/common.vcxproj.filters b/common/common.vcxproj.filters
index c660342c36..8f2bc35dd2 100644
--- a/common/common.vcxproj.filters
+++ b/common/common.vcxproj.filters
@@ -199,6 +199,9 @@
     <ClCompile Include="HTTPDownloaderWinHTTP.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="MemorySettingsInterface.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="AlignedMalloc.h">
@@ -468,6 +471,12 @@
     <ClInclude Include="ThreadPool.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="HeterogeneousContainers.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="MemorySettingsInterface.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Source Files">