diff --git a/modules/devices.py b/modules/devices.py
index ee679141a..556e72d2e 100644
--- a/modules/devices.py
+++ b/modules/devices.py
@@ -128,6 +128,26 @@ dtype_unet: torch.dtype = torch.float16
 dtype_inference: torch.dtype = torch.float16
 unet_needs_upcast = False
 
+supported_vae_dtypes = [torch.float16, torch.float32]
+
+
+# prepare available dtypes
+if torch.version.cuda:
+    if torch.cuda.is_bf16_supported() and torch.cuda.get_device_properties(torch.cuda.current_device()).major >= 8:
+        supported_vae_dtypes = [torch.bfloat16] + supported_vae_dtypes
+    if has_xpu():
+        supported_vae_dtypes = [torch.bfloat16] + supported_vae_dtypes
+
+
+def supports_non_blocking():
+    if has_mps() or has_xpu():
+        return False
+
+    if npu_specific.has_npu:
+        return False
+
+    return True
+
 
 def cond_cast_unet(input):
     if force_fp16:
@@ -149,14 +169,23 @@ patch_module_list = [
 ]
 
 
-def manual_cast_forward(target_dtype):
+def manual_cast_forward(target_dtype, target_device=None):
+    params = dict()
+    if supports_non_blocking():
+        params['non_blocking'] = True
+
     def forward_wrapper(self, *args, **kwargs):
-        if any(
-            isinstance(arg, torch.Tensor) and arg.dtype != target_dtype
-            for arg in args
-        ):
-            args = [arg.to(target_dtype) if isinstance(arg, torch.Tensor) else arg for arg in args]
-            kwargs = {k: v.to(target_dtype) if isinstance(v, torch.Tensor) else v for k, v in kwargs.items()}
+        if target_device is not None:
+            params['device'] = target_device
+        params['dtype'] = target_dtype
+
+        args = list(args)
+        for j in (i for i, arg in enumerate(args) if isinstance(arg, torch.Tensor) and arg.dtype != target_dtype):
+            args[j] = args[j].to(**params)
+        args = tuple(args)
+
+        for key in (k for k, v in kwargs.items() if isinstance(v, torch.Tensor) and v.dtype != target_dtype):
+            kwargs[key] = kwargs[key].to(**params)
 
         org_dtype = target_dtype
         for param in self.parameters():
@@ -165,37 +194,41 @@ def manual_cast_forward(target_dtype):
                 break
 
         if org_dtype != target_dtype:
-            self.to(target_dtype)
+            self.to(**params)
         result = self.org_forward(*args, **kwargs)
+
         if org_dtype != target_dtype:
-            self.to(org_dtype)
+            params['dtype'] = org_dtype
+            self.to(**params)
 
         if target_dtype != dtype_inference:
+            params['dtype'] = dtype_inference
             if isinstance(result, tuple):
                 result = tuple(
-                    i.to(dtype_inference)
+                    i.to(**params)
                     if isinstance(i, torch.Tensor)
                     else i
                     for i in result
                 )
             elif isinstance(result, torch.Tensor):
-                result = result.to(dtype_inference)
+                result = result.to(**params)
         return result
     return forward_wrapper
 
 
 @contextlib.contextmanager
-def manual_cast(target_dtype):
+def manual_cast(target_dtype, target_device=None):
     applied = False
+
     for module_type in patch_module_list:
         if hasattr(module_type, "org_forward"):
             continue
         applied = True
         org_forward = module_type.forward
         if module_type == torch.nn.MultiheadAttention:
-            module_type.forward = manual_cast_forward(torch.float32)
+            module_type.forward = manual_cast_forward(torch.float32, target_device)
         else:
-            module_type.forward = manual_cast_forward(target_dtype)
+            module_type.forward = manual_cast_forward(target_dtype, target_device)
         module_type.org_forward = org_forward
     try:
         yield None
@@ -207,26 +240,37 @@ def manual_cast(target_dtype):
                     delattr(module_type, "org_forward")
 
 
-def autocast(disable=False):
+def autocast(disable=False, current_dtype=None, target_dtype=None, target_device=None):
     if disable:
         return contextlib.nullcontext()
 
+    if target_dtype is None:
+        target_dtype = dtype
+    if target_device is None:
+        target_device = device
+
     if force_fp16:
         # No casting during inference if force_fp16 is enabled.
         # All tensor dtype conversion happens before inference.
         return contextlib.nullcontext()
 
-    if fp8 and device==cpu:
+    if fp8 and target_device==cpu:
         return torch.autocast("cpu", dtype=torch.bfloat16, enabled=True)
 
     if fp8 and dtype_inference == torch.float32:
-        return manual_cast(dtype)
+        return manual_cast(target_dtype, target_device)
 
-    if dtype == torch.float32 or dtype_inference == torch.float32:
+    if target_dtype != dtype_inference:
+        return manual_cast(target_dtype, target_device)
+
+    if current_dtype is not None and current_dtype != target_dtype:
+        return manual_cast(target_dtype, target_device)
+
+    if target_dtype == torch.float32 or dtype_inference == torch.float32:
         return contextlib.nullcontext()
 
     if has_xpu() or has_mps() or cuda_no_autocast():
-        return manual_cast(dtype)
+        return manual_cast(target_dtype, target_device)
 
     return torch.autocast("cuda")