diff --git a/source/tests/pt_expt/conftest.py b/source/tests/pt_expt/conftest.py
index f2a9b07a6a..3b48d2e51d 100644
--- a/source/tests/pt_expt/conftest.py
+++ b/source/tests/pt_expt/conftest.py
@@ -12,11 +12,21 @@
 """
 
 import pytest
+import torch._inductor.config as _inductor_config
 import torch.utils._device as _device
 from torch.overrides import (
     _get_current_function_mode_stack,
 )
 
+# Reduce AOTInductor (.pt2) compile time for unit tests.
+# Tests only validate correctness, not runtime performance, so we can
+# skip expensive C++ optimizations.  This cuts compile time by ~50%.
+_inductor_config.max_fusion_size = 8
+_inductor_config.epilogue_fusion = False
+_inductor_config.pattern_matcher = False
+_inductor_config.aot_inductor.package_cpp_only = True
+_inductor_config.aot_inductor.compile_wrapper_opt_level = "O0"
+
 
 def _pop_device_contexts() -> list:
     """Pop all stale DeviceContext modes from the torch function mode stack."""
diff --git a/source/tests/pt_expt/infer/test_deep_eval.py b/source/tests/pt_expt/infer/test_deep_eval.py
index 6797fa2c03..0bc9a90a79 100644
--- a/source/tests/pt_expt/infer/test_deep_eval.py
+++ b/source/tests/pt_expt/infer/test_deep_eval.py
@@ -544,12 +544,13 @@ def setUpClass(cls) -> None:
         cls.tmpfile = tempfile.NamedTemporaryFile(suffix=".pt2", delete=False)
         cls.tmpfile.close()
         # Temporarily clear default device to avoid poisoning AOTInductor
-        # compilation (tests/pt/__init__.py sets it to "cuda:9999999").
+        # compilation (tests/pt/__init__.py may set a fake CUDA device).
+        prev = torch.get_default_device()
         torch.set_default_device(None)
         try:
             deserialize_to_file(cls.tmpfile.name, cls.model_data)
         finally:
-            torch.set_default_device("cuda:9999999")
+            torch.set_default_device(prev)
 
         # Also save to .pte for cross-format comparison
         cls.pte_tmpfile = tempfile.NamedTemporaryFile(suffix=".pte", delete=False)
@@ -606,6 +607,7 @@ def test_get_model_def_script_with_params(self) -> None:
         with tempfile.NamedTemporaryFile(suffix=".pt2", delete=False) as f:
             tmpfile2 = f.name
         try:
+            prev = torch.get_default_device()
             torch.set_default_device(None)
             try:
                 data_with_config = {
@@ -614,7 +616,7 @@ def test_get_model_def_script_with_params(self) -> None:
                 }
                 deserialize_to_file(tmpfile2, data_with_config)
             finally:
-                torch.set_default_device("cuda:9999999")
+                torch.set_default_device(prev)
             dp2 = DeepPot(tmpfile2)
             mds = dp2.deep_eval.get_model_def_script()
             self.assertEqual(mds, training_config)
@@ -970,11 +972,12 @@ def setUpClass(cls) -> None:
         cls.model_data = {"model": cls.model.serialize()}
         cls.tmpfile = tempfile.NamedTemporaryFile(suffix=".pt2", delete=False)
         cls.tmpfile.close()
+        prev = torch.get_default_device()
         torch.set_default_device(None)
         try:
             deserialize_to_file(cls.tmpfile.name, cls.model_data)
         finally:
-            torch.set_default_device("cuda:9999999")
+            torch.set_default_device(prev)
 
         # Also save .pte for cross-format comparison
         cls.pte_tmpfile = tempfile.NamedTemporaryFile(suffix=".pte", delete=False)
@@ -1185,11 +1188,12 @@ def setUpClass(cls) -> None:
         cls.model_data = {"model": cls.model.serialize()}
         cls.tmpfile = tempfile.NamedTemporaryFile(suffix=".pt2", delete=False)
         cls.tmpfile.close()
+        prev = torch.get_default_device()
         torch.set_default_device(None)
         try:
             deserialize_to_file(cls.tmpfile.name, cls.model_data)
         finally:
-            torch.set_default_device("cuda:9999999")
+            torch.set_default_device(prev)
 
         # Also save .pte for cross-format comparison
         cls.pte_tmpfile = tempfile.NamedTemporaryFile(suffix=".pte", delete=False)