diff --git a/Common/File/DiskFree.h b/Common/File/DiskFree.h
index a08f44bdd1..a5a5fb3c68 100644
--- a/Common/File/DiskFree.h
+++ b/Common/File/DiskFree.h
@@ -5,4 +5,5 @@
 #include "Common/File/Path.h"
 
 // If this fails, false is returned and space is negative.
+// Try to avoid calling this from the main thread, if possible. Can be SLOW.
 bool free_disk_space(const Path &path, int64_t &space);
diff --git a/Core/FileSystems/BlobFileSystem.cpp b/Core/FileSystems/BlobFileSystem.cpp
index fb47eefa9d..ddcb20cc41 100644
--- a/Core/FileSystems/BlobFileSystem.cpp
+++ b/Core/FileSystems/BlobFileSystem.cpp
@@ -130,6 +130,6 @@ bool BlobFileSystem::RemoveFile(const std::string &filename) {
 	return false;
 }
 
-u64 BlobFileSystem::FreeSpace(const std::string &path) {
+u64 BlobFileSystem::FreeDiskSpace(const std::string &path) {
 	return 0;
 }
diff --git a/Core/FileSystems/BlobFileSystem.h b/Core/FileSystems/BlobFileSystem.h
index 6def55870d..adb4440c90 100644
--- a/Core/FileSystems/BlobFileSystem.h
+++ b/Core/FileSystems/BlobFileSystem.h
@@ -52,7 +52,7 @@ public:
 	bool RmDir(const std::string &dirname) override;
 	int  RenameFile(const std::string &from, const std::string &to) override;
 	bool RemoveFile(const std::string &filename) override;
-	u64 FreeSpace(const std::string &path) override;
+	u64 FreeDiskSpace(const std::string &path) override;
 
 	bool ComputeRecursiveDirSizeIfFast(const std::string &path, int64_t *size) override { return false; }
 
diff --git a/Core/FileSystems/DirectoryFileSystem.cpp b/Core/FileSystems/DirectoryFileSystem.cpp
index f3948bf347..eb2d6c68d4 100644
--- a/Core/FileSystems/DirectoryFileSystem.cpp
+++ b/Core/FileSystems/DirectoryFileSystem.cpp
@@ -871,7 +871,7 @@ std::vector<PSPFileInfo> DirectoryFileSystem::GetDirListing(const std::string &p
 	return ReplayApplyDiskListing(myVector, CoreTiming::GetGlobalTimeUs());
 }
 
-u64 DirectoryFileSystem::FreeSpace(const std::string &path) {
+u64 DirectoryFileSystem::FreeDiskSpace(const std::string &path) {
 	int64_t result = 0;
 	if (free_disk_space(GetLocalPath(path), result)) {
 		return ReplayApplyDisk64(ReplayAction::FREESPACE, (uint64_t)result, CoreTiming::GetGlobalTimeUs());
diff --git a/Core/FileSystems/DirectoryFileSystem.h b/Core/FileSystems/DirectoryFileSystem.h
index 965a90f8fc..d0a9f9d6f5 100644
--- a/Core/FileSystems/DirectoryFileSystem.h
+++ b/Core/FileSystems/DirectoryFileSystem.h
@@ -83,7 +83,7 @@ public:
 	int  RenameFile(const std::string &from, const std::string &to) override;
 	bool RemoveFile(const std::string &filename) override;
 	FileSystemFlags Flags() override { return flags; }
-	u64 FreeSpace(const std::string &path) override;
+	u64 FreeDiskSpace(const std::string &path) override;
 
 	bool ComputeRecursiveDirSizeIfFast(const std::string &path, int64_t *size) override;
 
@@ -129,7 +129,7 @@ public:
 	int  RenameFile(const std::string &from, const std::string &to) override;
 	bool RemoveFile(const std::string &filename) override;
 	FileSystemFlags Flags() override { return FileSystemFlags::FLASH; }
-	u64 FreeSpace(const std::string &path) override { return 0; }
+	u64 FreeDiskSpace(const std::string &path) override { return 0; }
 
 	bool ComputeRecursiveDirSizeIfFast(const std::string &path, int64_t *size) override { return false; }
 
diff --git a/Core/FileSystems/FileSystem.h b/Core/FileSystems/FileSystem.h
index 693c1a55d9..27953fe76c 100644
--- a/Core/FileSystems/FileSystem.h
+++ b/Core/FileSystems/FileSystem.h
@@ -145,7 +145,7 @@ public:
 	virtual int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) = 0;
 	virtual PSPDevType DevType(u32 handle) = 0;
 	virtual FileSystemFlags Flags() = 0;
-	virtual u64      FreeSpace(const std::string &path) = 0;
+	virtual u64      FreeDiskSpace(const std::string &path) = 0;
 	virtual bool     ComputeRecursiveDirSizeIfFast(const std::string &path, int64_t *size) = 0;
 };
 
@@ -175,7 +175,7 @@ public:
 	int Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) override { return SCE_KERNEL_ERROR_ERRNO_FUNCTION_NOT_SUPPORTED; }
 	PSPDevType DevType(u32 handle) override { return PSPDevType::INVALID; }
 	FileSystemFlags Flags() override { return FileSystemFlags::NONE; }
-	u64 FreeSpace(const std::string &path) override { return 0; }
+	u64 FreeDiskSpace(const std::string &path) override { return 0; }
 	bool ComputeRecursiveDirSizeIfFast(const std::string &path, int64_t *size) override { return false; }
 };
 
diff --git a/Core/FileSystems/ISOFileSystem.h b/Core/FileSystems/ISOFileSystem.h
index 668c4d7174..492fcf9b2b 100644
--- a/Core/FileSystems/ISOFileSystem.h
+++ b/Core/FileSystems/ISOFileSystem.h
@@ -44,7 +44,7 @@ public:
 	int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) override;
 	PSPDevType DevType(u32 handle) override;
 	FileSystemFlags Flags() override;
-	u64      FreeSpace(const std::string &path) override { return 0; }
+	u64      FreeDiskSpace(const std::string &path) override { return 0; }
 
 	size_t WriteFile(u32 handle, const u8 *pointer, s64 size) override;
 	size_t WriteFile(u32 handle, const u8 *pointer, s64 size, int &usec) override;
@@ -146,7 +146,7 @@ public:
 		return isoFileSystem_->DevType(handle);
 	}
 	FileSystemFlags Flags() override { return isoFileSystem_->Flags(); }
-	u64      FreeSpace(const std::string &path) override { return isoFileSystem_->FreeSpace(path); }
+	u64      FreeDiskSpace(const std::string &path) override { return isoFileSystem_->FreeDiskSpace(path); }
 
 	size_t WriteFile(u32 handle, const u8 *pointer, s64 size) override {
 		return isoFileSystem_->WriteFile(handle, pointer, size);
diff --git a/Core/FileSystems/MetaFileSystem.cpp b/Core/FileSystems/MetaFileSystem.cpp
index adc86c0ebb..1ab0e2cb94 100644
--- a/Core/FileSystems/MetaFileSystem.cpp
+++ b/Core/FileSystems/MetaFileSystem.cpp
@@ -606,20 +606,18 @@ int MetaFileSystem::ReadEntireFile(const std::string &filename, std::vector<u8>
 	return 0;
 }
 
-u64 MetaFileSystem::FreeSpace(const std::string &path)
-{
+u64 MetaFileSystem::FreeDiskSpace(const std::string &path) {
 	std::lock_guard<std::recursive_mutex> guard(lock);
 	std::string of;
 	IFileSystem *system;
 	int error = MapFilePath(path, of, &system);
 	if (error == 0)
-		return system->FreeSpace(of);
+		return system->FreeDiskSpace(of);
 	else
 		return 0;
 }
 
-void MetaFileSystem::DoState(PointerWrap &p)
-{
+void MetaFileSystem::DoState(PointerWrap &p) {
 	std::lock_guard<std::recursive_mutex> guard(lock);
 
 	auto s = p.Section("MetaFileSystem", 1);
@@ -634,8 +632,7 @@ void MetaFileSystem::DoState(PointerWrap &p)
 	u32 n = (u32) fileSystems.size();
 	Do(p, n);
 	bool skipPfat0 = false;
-	if (n != (u32) fileSystems.size())
-	{
+	if (n != (u32) fileSystems.size()) {
 		if (n == (u32) fileSystems.size() - 1) {
 			skipPfat0 = true;
 		} else {
diff --git a/Core/FileSystems/MetaFileSystem.h b/Core/FileSystems/MetaFileSystem.h
index 0a2255566f..54cc5c9d8f 100644
--- a/Core/FileSystems/MetaFileSystem.h
+++ b/Core/FileSystems/MetaFileSystem.h
@@ -127,7 +127,7 @@ public:
 	int  Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) override;
 	PSPDevType DevType(u32 handle) override;
 	FileSystemFlags Flags() override { return FileSystemFlags::NONE; }
-	u64  FreeSpace(const std::string &path) override;
+	u64  FreeDiskSpace(const std::string &path) override;
 
 	// Convenience helper - returns < 0 on failure.
 	int ReadEntireFile(const std::string &filename, std::vector<u8> &data, bool quiet = false);
diff --git a/Core/FileSystems/VirtualDiscFileSystem.h b/Core/FileSystems/VirtualDiscFileSystem.h
index d2839ad21b..e8110e0b2d 100644
--- a/Core/FileSystems/VirtualDiscFileSystem.h
+++ b/Core/FileSystems/VirtualDiscFileSystem.h
@@ -44,7 +44,7 @@ public:
 	PSPDevType DevType(u32 handle) override;
 	std::vector<PSPFileInfo> GetDirListing(const std::string &path, bool *exists = nullptr) override;
 	FileSystemFlags Flags() override { return FileSystemFlags::UMD; }
-	u64  FreeSpace(const std::string &path) override { return 0; }
+	u64  FreeDiskSpace(const std::string &path) override { return 0; }
 
 	// unsupported operations
 	size_t  WriteFile(u32 handle, const u8 *pointer, s64 size) override;
diff --git a/Core/HW/MemoryStick.cpp b/Core/HW/MemoryStick.cpp
index 8511a9d76c..8d503f8694 100644
--- a/Core/HW/MemoryStick.cpp
+++ b/Core/HW/MemoryStick.cpp
@@ -103,7 +103,7 @@ static void MemoryStick_CalcInitialFree() {
 
 		AndroidJNIThreadContext jniContext;
 
-		memstickInitialFree = pspFileSystem.FreeSpace("ms0:/") + pspFileSystem.ComputeRecursiveDirectorySize("ms0:/PSP/SAVEDATA/");
+		memstickInitialFree = pspFileSystem.FreeDiskSpace("ms0:/") + pspFileSystem.ComputeRecursiveDirectorySize("ms0:/PSP/SAVEDATA/");
 
 		std::unique_lock<std::mutex> guard(freeCalcMutex);
 		freeCalcStatus = FreeCalcStatus::DONE;
@@ -122,10 +122,12 @@ static void MemoryStick_WaitInitialFree() {
 }
 
 u64 MemoryStick_FreeSpace() {
+	NOTICE_LOG(Log::IO, "Calculated free disk space");
+
 	MemoryStick_WaitInitialFree();
 
 	const CompatFlags &flags = PSP_CoreParameter().compat.flags();
-	u64 realFreeSpace = pspFileSystem.FreeSpace("ms0:/");
+	u64 realFreeSpace = pspFileSystem.FreeDiskSpace("ms0:/");
 
 	// Cap the memory stick size to avoid math errors when old games get sizes that were
 	// not planned for back then (even though 2GB cards were available.)
diff --git a/UI/MemStickScreen.cpp b/UI/MemStickScreen.cpp
index d7f28bbf57..fffb2f8321 100644
--- a/UI/MemStickScreen.cpp
+++ b/UI/MemStickScreen.cpp
@@ -470,6 +470,14 @@ ConfirmMemstickMoveScreen::~ConfirmMemstickMoveScreen() {
 		moveDataTask_->BlockUntilReady();
 		delete moveDataTask_;
 	}
+	if (oldSpaceTask_) {
+		oldSpaceTask_->BlockUntilReady();
+		delete oldSpaceTask_;
+	}
+	if (newSpaceTask_) {
+		newSpaceTask_->BlockUntilReady();
+		delete newSpaceTask_;
+	}
 }
 
 void ConfirmMemstickMoveScreen::CreateViews() {
@@ -479,7 +487,7 @@ void ConfirmMemstickMoveScreen::CreateViews() {
 
 	root_ = new LinearLayout(ORIENT_HORIZONTAL);
 
-	Path oldMemstickFolder = g_Config.memStickDirectory;
+	Path &oldMemstickFolder = g_Config.memStickDirectory;
 
 	Spacer *spacerColumn = new Spacer(new LinearLayoutParams(20.0, FILL_PARENT, 0.0f));
 	ViewGroup *leftColumn = new LinearLayout(ORIENT_VERTICAL, new LinearLayoutParams(1.0));
@@ -488,18 +496,20 @@ void ConfirmMemstickMoveScreen::CreateViews() {
 	root_->Add(leftColumn);
 	root_->Add(rightColumn);
 
-	int64_t freeSpaceNew;
-	int64_t freeSpaceOld;
-	free_disk_space(newMemstickFolder_, freeSpaceNew);
-	free_disk_space(oldMemstickFolder, freeSpaceOld);
-
 	leftColumn->Add(new TextView(ms->T("Selected PSP Data Folder"), ALIGN_LEFT, false));
 	if (!initialSetup_) {
 		leftColumn->Add(new NoticeView(NoticeLevel::WARN, ms->T("PPSSPP will restart after the change"), ""));
 	}
 	leftColumn->Add(new TextView(newMemstickFolder_.ToVisualString(), ALIGN_LEFT, false));
-	std::string newFreeSpaceText = std::string(ms->T("Free space")) + ": " + FormatSpaceString(freeSpaceNew);
-	leftColumn->Add(new TextView(newFreeSpaceText, ALIGN_LEFT, false));
+
+	newFreeSpaceView_ = leftColumn->Add(new TextView(ms->T("Free space"), ALIGN_LEFT, false));
+
+	newSpaceTask_ = Promise<SpaceResult *>::Spawn(&g_threadManager, [&]() -> SpaceResult * {
+		int64_t freeSpaceNew;
+		free_disk_space(newMemstickFolder_, freeSpaceNew);
+		return new SpaceResult{ freeSpaceNew };
+	}, TaskType::IO_BLOCKING, TaskPriority::HIGH);
+
 	if (existingFilesInNewFolder_) {
 		leftColumn->Add(new NoticeView(NoticeLevel::SUCCESS, ms->T("Already contains PSP data"), ""));
 		if (!moveData_) {
@@ -511,11 +521,15 @@ void ConfirmMemstickMoveScreen::CreateViews() {
 	}
 
 	if (!oldMemstickFolder.empty()) {
-		std::string oldFreeSpaceText = std::string(ms->T("Free space")) + ": " + FormatSpaceString(freeSpaceOld);
+		oldSpaceTask_ = Promise<SpaceResult *>::Spawn(&g_threadManager, [&]() -> SpaceResult * {
+			int64_t freeSpaceOld;
+			free_disk_space(oldMemstickFolder, freeSpaceOld);
+			return new SpaceResult{ freeSpaceOld };
+		}, TaskType::IO_BLOCKING, TaskPriority::HIGH);
 
 		rightColumn->Add(new TextView(std::string(ms->T("Current")) + ":", ALIGN_LEFT, false));
 		rightColumn->Add(new TextView(oldMemstickFolder.ToVisualString(), ALIGN_LEFT, false));
-		rightColumn->Add(new TextView(oldFreeSpaceText, ALIGN_LEFT, false));
+		oldFreeSpaceView_ = rightColumn->Add(new TextView(ms->T("Free space"), ALIGN_LEFT, false));
 	}
 
 	if (moveDataTask_) {
@@ -567,6 +581,23 @@ void ConfirmMemstickMoveScreen::update() {
 			moveDataTask_ = nullptr;
 		}
 	}
+
+	if (newSpaceTask_ && newFreeSpaceView_) {
+		SpaceResult *result = newSpaceTask_->Poll();
+		if (result) {
+			newFreeSpaceView_->SetText(std::string(ms->T("Free space")) + ": " + FormatSpaceString(result->bytesFree));
+			delete newSpaceTask_;
+			newSpaceTask_ = nullptr;
+		}
+	}
+	if (oldSpaceTask_ && oldFreeSpaceView_) {
+		SpaceResult *result = oldSpaceTask_->Poll();
+		if (result) {
+			oldFreeSpaceView_->SetText(std::string(ms->T("Free space")) + ": " + FormatSpaceString(result->bytesFree));
+			delete oldSpaceTask_;
+			oldSpaceTask_ = nullptr;
+		}
+	}
 }
 
 UI::EventReturn ConfirmMemstickMoveScreen::OnConfirm(UI::EventParams &params) {
diff --git a/UI/MemStickScreen.h b/UI/MemStickScreen.h
index cb10cffe72..e65b458335 100644
--- a/UI/MemStickScreen.h
+++ b/UI/MemStickScreen.h
@@ -93,6 +93,10 @@ private:
 #endif
 };
 
+struct SpaceResult {
+	int64_t bytesFree;
+};
+
 class ConfirmMemstickMoveScreen : public UIDialogScreenWithBackground {
 public:
 	ConfirmMemstickMoveScreen(const Path &newMemstickFolder, bool initialSetup);
@@ -121,8 +125,12 @@ private:
 
 	MoveProgressReporter progressReporter_;
 	UI::TextView *progressView_ = nullptr;
+	UI::TextView *newFreeSpaceView_ = nullptr;
+	UI::TextView *oldFreeSpaceView_ = nullptr;
 
 	Promise<MoveResult *> *moveDataTask_ = nullptr;
+	Promise<SpaceResult *> *oldSpaceTask_ = nullptr;
+	Promise<SpaceResult *> *newSpaceTask_ = nullptr;
 
 	std::string error_;
 };