diff --git a/.github/canary-scale-config.yml b/.github/canary-scale-config.yml
index 4370a76beb..2b6a7c7e3d 100644
--- a/.github/canary-scale-config.yml
+++ b/.github/canary-scale-config.yml
@@ -237,6 +237,26 @@ runner_types:
         ami: Windows 2019 GHA CI - 20250812161628|308535385114
       wincanarylf:
         ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  c.windows.12xlarge:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  c.windows.12xlarge.nonephemeral:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
   c.windows.8xlarge.nvidia.gpu:
     disk_size: 256
     instance_type: p3.2xlarge
diff --git a/.github/lf-canary-scale-config.yml b/.github/lf-canary-scale-config.yml
index d6ffc26fbe..611aca29d7 100644
--- a/.github/lf-canary-scale-config.yml
+++ b/.github/lf-canary-scale-config.yml
@@ -237,6 +237,26 @@ runner_types:
         ami: Windows 2019 GHA CI - 20250812161628|308535385114
       wincanarylf:
         ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  lf.c.windows.12xlarge:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  lf.c.windows.12xlarge.nonephemeral:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
   lf.c.windows.8xlarge.nvidia.gpu:
     disk_size: 256
     instance_type: p3.2xlarge
diff --git a/.github/lf-scale-config.yml b/.github/lf-scale-config.yml
index 698def8427..559b1f5090 100644
--- a/.github/lf-scale-config.yml
+++ b/.github/lf-scale-config.yml
@@ -237,6 +237,26 @@ runner_types:
         ami: Windows 2019 GHA CI - 20250812161628|308535385114
       wincanarylf:
         ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  lf.windows.12xlarge:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  lf.windows.12xlarge.nonephemeral:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
   lf.windows.8xlarge.nvidia.gpu:
     disk_size: 256
     instance_type: p3.2xlarge
diff --git a/.github/scale-config.yml b/.github/scale-config.yml
index 2da260a80a..d6abc33c66 100644
--- a/.github/scale-config.yml
+++ b/.github/scale-config.yml
@@ -233,6 +233,26 @@ runner_types:
         ami: Windows 2019 GHA CI - 20250812161628|308535385114
       wincanarylf:
         ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  windows.12xlarge:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
+  windows.12xlarge.nonephemeral:
+    disk_size: 256
+    instance_type: c5d.12xlarge
+    is_ephemeral: true
+    os: windows
+    variants:
+      wincanary:
+        ami: Windows 2019 GHA CI - 20250812161628|308535385114
+      wincanarylf:
+        ami: Windows 2019 GHA CI - 20250825191007|391835788720
   windows.8xlarge.nvidia.gpu:
     disk_size: 256
     instance_type: p3.2xlarge