diff --git a/.github/workflows/swift-toolchain.yml b/.github/workflows/swift-toolchain.yml
index d8d45276c..caa5ff783 100644
--- a/.github/workflows/swift-toolchain.yml
+++ b/.github/workflows/swift-toolchain.yml
@@ -783,45 +783,65 @@ jobs:
             triple: 'aarch64-unknown-windows-msvc'
 
     steps:
+      - name: Create Dev Drive using ReFS
+        run: |
+          $Volume = New-VHD -Path C:/uv_dev_drive.vhdx -SizeBytes 500GB |
+                    Mount-VHD -Passthru |
+                    Initialize-Disk -Passthru |
+                    New-Partition -AssignDriveLetter -UseMaximumSize |
+                    Format-Volume -FileSystem ReFS -Confirm:$false -Force
+          Write-Output $Volume
+          Write-Output "DEV_DRIVE=$($Volume.DriveLetter):" >> $env:GITHUB_ENV
+      - name: Copy Git Repo to Dev Drive & Add Symbolic Link
+        run: |
+          Copy-Item -Path "${{ github.workspace }}" -Destination "${{ env.DEV_DRIVE }}" -Recurse
+          mkdir "${{ github.workspace }}/refs"
+          New-Item -Path "${{ github.workspace }}/refs" -ItemType SymbolicLink -Value "${{ env.DEV_DRIVE }}"
+
       - uses: actions/download-artifact@v4
         with:
           name: build-tools
-          path: ${{ github.workspace }}/BinaryCache/0/bin
+          path: ${{ env.DEV_DRIVE }}/BinaryCache/0/bin
       - uses: actions/download-artifact@v4
         with:
           name: cmark-gfm-${{ matrix.arch }}-0.29.0.gfm.13
-          path: ${{ github.workspace }}/BuildRoot/Library/cmark-gfm-0.29.0.gfm.13/usr
+          path: ${{ env.DEV_DRIVE }}/BuildRoot/Library/cmark-gfm-0.29.0.gfm.13/usr
 
       - uses: actions/checkout@v4
         with:
           repository: apple/llvm-project
           ref: ${{ needs.context.outputs.llvm_project_revision }}
-          path: ${{ github.workspace }}/SourceCache/llvm-project
+          path: ${{ env.DEV_DRIVE }}/SourceCache/llvm-project
           show-progress: false
+          symlink: true
       - uses: actions/checkout@v4
         with:
           repository: apple/swift
           ref: ${{ needs.context.outputs.swift_revision }}
-          path: ${{ github.workspace }}/SourceCache/swift
+          path: ${{ env.DEV_DRIVE }}/SourceCache/swift
           show-progress: false
+          symlink: true
       - uses: actions/checkout@v4
         with:
           repository: apple/swift-experimental-string-processing
           ref: ${{ needs.context.outputs.swift_experimental_string_processing_revision }}
-          path: ${{ github.workspace }}/SourceCache/swift-experimental-string-processing
+          path: ${{ env.DEV_DRIVE }}/SourceCache/swift-experimental-string-processing
           show-progress: false
+          symlink: true
       - uses: actions/checkout@v4
         with:
           repository: apple/swift-syntax
           ref: ${{ needs.context.outputs.swift_syntax_revision }}
-          path: ${{ github.workspace }}/SourceCache/swift-syntax
+          path: ${{ env.DEV_DRIVE }}/SourceCache/swift-syntax
           show-progress: false
+          symlink: true
       - uses: actions/checkout@v4
         with:
           repository: apple/swift-corelibs-libdispatch
           ref: ${{ needs.context.outputs.swift_corelibs_libdispatch_revision }}
-          path: ${{ github.workspace }}/SourceCache/swift-corelibs-libdispatch
+          path: ${{ env.DEV_DRIVE }}/SourceCache/swift-corelibs-libdispatch
           show-progress: false
+          symlink: true
 
       - name: Install Python ${{ env.PYTHON_VERSION }} (Host)
         uses: actions/setup-python@v5
@@ -845,7 +865,7 @@ jobs:
       - name: Export Python Location
         run: |
           echo "PYTHON_LOCATION_amd64=$env:pythonLocation" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
-          echo "PYTHON_LOCATION_arm64=${{ github.workspace }}\pythonarm64.${{ env.PYTHON_VERSION }}\tools" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+          echo "PYTHON_LOCATION_arm64=${{ env.DEV_DRIVE }}\pythonarm64.${{ env.PYTHON_VERSION }}\tools" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
 
       - uses: compnerd/gha-setup-vsdevenv@main
         with:
@@ -884,7 +904,7 @@ jobs:
             $CACHE="Windows-aarch64.cmake"
 
             # FIXME(compnerd) re-enable runtimes after we sort out compiler-rt
-            (Get-Content ${{ github.workspace }}/SourceCache/swift/cmake/caches/Windows-aarch64.cmake).Replace(' runtimes', '') | Set-Content ${{ github.workspace }}/SourceCache/swift/cmake/caches/Windows-aarch64.cmake
+            (Get-Content ${{ env.DEV_DRIVE }}/SourceCache/swift/cmake/caches/Windows-aarch64.cmake).Replace(' runtimes', '') | Set-Content ${{ env.DEV_DRIVE }}/SourceCache/swift/cmake/caches/Windows-aarch64.cmake
           } else {
             $CACHE="Windows-x86_64.cmake"
           }
@@ -893,8 +913,8 @@ jobs:
           # Use toolchain clang to avoid broken __prefetch intrinsic on arm64 in Clang 18.
           $CLANG_LOCATION = cygpath -m (Split-Path (Get-Command swiftc).Source)
           Remove-Item env:\SDKROOT
-          cmake -B ${{ github.workspace }}/BinaryCache/1 `
-                -C ${{ github.workspace }}/SourceCache/swift/cmake/caches/${CACHE} `
+          cmake -B ${{ env.DEV_DRIVE }}/BinaryCache/1 `
+                -C ${{ env.DEV_DRIVE }}/SourceCache/swift/cmake/caches/${CACHE} `
                 -D CMAKE_BUILD_TYPE=Release `
                 -D CMAKE_C_COMPILER=cl `
                 -D CMAKE_C_COMPILER_LAUNCHER=sccache `
@@ -907,19 +927,19 @@ jobs:
                 -D CMAKE_Swift_COMPILER_WORKS=YES `
                 -D CMAKE_Swift_FLAGS="-sdk `"${SDKROOT}`" -Xcc -D_ALLOW_COMPILER_AND_STL_VERSION_MISMATCH" `
                 -D CMAKE_EXE_LINKER_FLAGS="${{ needs.context.outputs.WINDOWS_CMAKE_EXE_LINKER_FLAGS }}" `
-                -D CMAKE_INSTALL_PREFIX=${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr `
+                -D CMAKE_INSTALL_PREFIX=${{ env.DEV_DRIVE }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr `
                 -D CMAKE_SHARED_LINKER_FLAGS="${{ needs.context.outputs.WINDOWS_CMAKE_SHARED_LINKER_FLAGS }}" `
                 ${CMAKE_SYSTEM_NAME} `
                 ${CMAKE_SYSTEM_PROCESSOR} `
                 -G Ninja `
-                -S ${{ github.workspace }}/SourceCache/llvm-project/llvm `
-                -D CLANG_TABLEGEN=${{ github.workspace }}/BinaryCache/0/bin/clang-tblgen.exe `
-                -D CLANG_TIDY_CONFUSABLE_CHARS_GEN=${{ github.workspace }}/BinaryCache/0/bin/clang-tidy-confusable-chars-gen.exe `
-                -D LLDB_TABLEGEN=${{ github.workspace }}/BinaryCache/0/bin/lldb-tblgen.exe `
-                -D LLVM_CONFIG_PATH=${{ github.workspace }}/BinaryCache/0/bin/llvm-config.exe `
-                -D LLVM_EXTERNAL_SWIFT_SOURCE_DIR=${{ github.workspace }}/SourceCache/swift `
-                -D LLVM_NATIVE_TOOL_DIR=${{ github.workspace }}/BinaryCache/0/bin `
-                -D LLVM_TABLEGEN=${{ github.workspace }}/BinaryCache/0/bin/llvm-tblgen.exe `
+                -S ${{ env.DEV_DRIVE }}/SourceCache/llvm-project/llvm `
+                -D CLANG_TABLEGEN=${{ env.DEV_DRIVE }}/BinaryCache/0/bin/clang-tblgen.exe `
+                -D CLANG_TIDY_CONFUSABLE_CHARS_GEN=${{ env.DEV_DRIVE }}/BinaryCache/0/bin/clang-tidy-confusable-chars-gen.exe `
+                -D LLDB_TABLEGEN=${{ env.DEV_DRIVE }}/BinaryCache/0/bin/lldb-tblgen.exe `
+                -D LLVM_CONFIG_PATH=${{ env.DEV_DRIVE }}/BinaryCache/0/bin/llvm-config.exe `
+                -D LLVM_EXTERNAL_SWIFT_SOURCE_DIR=${{ env.DEV_DRIVE }}/SourceCache/swift `
+                -D LLVM_NATIVE_TOOL_DIR=${{ env.DEV_DRIVE }}/BinaryCache/0/bin `
+                -D LLVM_TABLEGEN=${{ env.DEV_DRIVE }}/BinaryCache/0/bin/llvm-tblgen.exe `
                 -D LLVM_USE_HOST_TOOLS=NO `
                 -D SWIFT_BUILD_DYNAMIC_SDK_OVERLAY=NO `
                 -D SWIFT_BUILD_DYNAMIC_STDLIB=NO `
@@ -933,14 +953,14 @@ jobs:
                 -D SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION=YES `
                 -D SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING=YES `
                 -D SWIFT_ENABLE_SYNCHRONIZATION=YES `
-                -D SWIFT_NATIVE_SWIFT_TOOLS_PATH=${{ github.workspace }}/BinaryCache/0/bin `
-                -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE=${{ github.workspace }}/SourceCache/swift-corelibs-libdispatch `
-                -D SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE=${{ github.workspace }}/SourceCache/swift-syntax `
-                -D SWIFT_PATH_TO_STRING_PROCESSING_SOURCE=${{ github.workspace }}/SourceCache/swift-experimental-string-processing `
+                -D SWIFT_NATIVE_SWIFT_TOOLS_PATH=${{ env.DEV_DRIVE }}/BinaryCache/0/bin `
+                -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE=${{ env.DEV_DRIVE }}/SourceCache/swift-corelibs-libdispatch `
+                -D SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE=${{ env.DEV_DRIVE }}/SourceCache/swift-syntax `
+                -D SWIFT_PATH_TO_STRING_PROCESSING_SOURCE=${{ env.DEV_DRIVE }}/SourceCache/swift-experimental-string-processing `
                 -D SWIFT_PATH_TO_SWIFT_SDK="${SDKROOT}" `
                 -D CLANG_VENDOR=compnerd.org `
                 -D CLANG_VENDOR_UTI=org.compnerd.dt `
-                -D cmark-gfm_DIR=${{ github.workspace }}/BuildRoot/Library/cmark-gfm-0.29.0.gfm.13/usr/lib/cmake `
+                -D cmark-gfm_DIR=${{ env.DEV_DRIVE }}/BuildRoot/Library/cmark-gfm-0.29.0.gfm.13/usr/lib/cmake `
                 -D PACKAGE_VENDOR=compnerd.org `
                 -D SWIFT_VENDOR=compnerd.org `
                 -D LLVM_PARALLEL_LINK_JOBS=8 `
@@ -956,34 +976,34 @@ jobs:
                 -D Python3_ROOT_DIR=$env:pythonLocation
 
       - name: Build Compiler Distribution
-        run: cmake --build ${{ github.workspace }}/BinaryCache/1 --target distribution
+        run: cmake --build ${{ env.DEV_DRIVE }}/BinaryCache/1 --target distribution
 
       - name: Install Compiler Distribution
-        run: cmake --build ${{ github.workspace }}/BinaryCache/1 --target install-distribution-stripped
+        run: cmake --build ${{ env.DEV_DRIVE }}/BinaryCache/1 --target install-distribution-stripped
 
       - name: Upload Compilers
         uses: actions/upload-artifact@v4
         with:
           name: compilers-${{ matrix.arch }}
-          path: ${{ github.workspace }}/BuildRoot/Library
+          path: ${{ env.DEV_DRIVE }}/BuildRoot/Library
 
       - name: extract swift-syntax
         run: |
-          $module = "${{ github.workspace }}/BinaryCache/1/cmake/modules/SwiftSyntaxConfig.cmake"
-          $bindir = cygpath -m ${{ github.workspace }}/BinaryCache/1
+          $module = "${{ env.DEV_DRIVE }}/BinaryCache/1/cmake/modules/SwiftSyntaxConfig.cmake"
+          $bindir = cygpath -m ${{ env.DEV_DRIVE }}/BinaryCache/1
           (Get-Content $module).Replace("${bindir}", '<BINARY_DIR>') | Set-Content $module
-          New-Item -Path ${{ github.workspace }}/BinaryCache/swift-syntax/lib/swift/host -ItemType Directory | Out-Null
-          Copy-Item -Path "${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/*.lib" -Destination "${{ github.workspace }}/BinaryCache/swift-syntax/lib"
-          Copy-Item -Path "${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/*.lib" -Destination "${{ github.workspace }}/BinaryCache/swift-syntax/lib/swift/host"
-          Copy-Item -Path "${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/swift/host/*.swiftmodule" -Destination "${{ github.workspace }}/BinaryCache/swift-syntax/lib/swift/host" -Recurse
-          New-Item -Path ${{ github.workspace }}/BinaryCache/swift-syntax/cmake/modules -ItemType Directory | Out-Null
-          Copy-Item -Path $module -Destination "${{ github.workspace }}/BinaryCache/swift-syntax/cmake/modules"
+          New-Item -Path ${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/lib/swift/host -ItemType Directory | Out-Null
+          Copy-Item -Path "${{ env.DEV_DRIVE }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/*.lib" -Destination "${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/lib"
+          Copy-Item -Path "${{ env.DEV_DRIVE }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/*.lib" -Destination "${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/lib/swift/host"
+          Copy-Item -Path "${{ env.DEV_DRIVE }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/swift/host/*.swiftmodule" -Destination "${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/lib/swift/host" -Recurse
+          New-Item -Path ${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/cmake/modules -ItemType Directory | Out-Null
+          Copy-Item -Path $module -Destination "${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax/cmake/modules"
 
       - name: Upload swift-syntax
         uses: actions/upload-artifact@v4
         with:
           name: swift-syntax-${{ matrix.arch }}
-          path: ${{ github.workspace }}/BinaryCache/swift-syntax
+          path: ${{ env.DEV_DRIVE }}/BinaryCache/swift-syntax
 
       # TODO(compnerd) this takes ~1h due to the size, see if we can compress first
       - uses: actions/upload-artifact@v4
@@ -991,7 +1011,7 @@ jobs:
         with:
           name: compilers-${{ matrix.arch }}-debug-info
           path: |
-            ${{ github.workspace }}/BinaryCache/1/**/*.pdb
+            ${{ env.DEV_DRIVE }}/BinaryCache/1/**/*.pdb
 
       - name: Upload PDBs to Azure
         uses: microsoft/action-publish-symbols@v2.1.6
@@ -999,7 +1019,7 @@ jobs:
         with:
           accountName: ${{ vars.SYMBOL_SERVER_ACCOUNT }}
           personalAccessToken: ${{ secrets.SYMBOL_SERVER_PAT }}
-          symbolsFolder: ${{ github.workspace }}/BinaryCache/1
+          symbolsFolder: ${{ env.DEV_DRIVE }}/BinaryCache/1
           searchPattern: '**/*.pdb'
 
       - name: Upload DLLs to Azure
@@ -1008,7 +1028,7 @@ jobs:
         with:
           accountName: ${{ vars.SYMBOL_SERVER_ACCOUNT }}
           personalAccessToken: ${{ secrets.SYMBOL_SERVER_PAT }}
-          symbolsFolder: ${{ github.workspace }}/BinaryCache/1
+          symbolsFolder: ${{ env.DEV_DRIVE }}/BinaryCache/1
           searchPattern: '**/*.dll'
 
       - name: Upload EXEs to Azure
@@ -1017,7 +1037,7 @@ jobs:
         with:
           accountName: ${{ vars.SYMBOL_SERVER_ACCOUNT }}
           personalAccessToken: ${{ secrets.SYMBOL_SERVER_PAT }}
-          symbolsFolder: ${{ github.workspace }}/BinaryCache/1
+          symbolsFolder: ${{ env.DEV_DRIVE }}/BinaryCache/1
           searchPattern: '**/*.exe'
 
   zlib: