diff --git a/ui/sd_internal/runtime.py b/ui/sd_internal/runtime.py
index 34bb8c7a..9ed8404f 100644
--- a/ui/sd_internal/runtime.py
+++ b/ui/sd_internal/runtime.py
@@ -1,3 +1,9 @@
+"""runtime.py: torch device owned by a thread.
+Notes:
+    Avoid device switching, transfering all models will get too complex.
+    To use a diffrent device signal the current render device to exit
+    And then start a new clean thread for the new device.
+"""
 import json
 import os, re
 import traceback
diff --git a/ui/sd_internal/task_manager.py b/ui/sd_internal/task_manager.py
index 4bd1d549..10d66fd4 100644
--- a/ui/sd_internal/task_manager.py
+++ b/ui/sd_internal/task_manager.py
@@ -1,3 +1,9 @@
+"""task_manager.py: manage tasks dispatching and render threads.
+Notes:
+    render_threads should be the only hard reference held by the manager to the threads.
+    Use weak_thread_data to store all other data using weak keys.
+    This will allow for garbage collection after the thread dies.
+"""
 import json
 import traceback
 
@@ -340,6 +346,11 @@ def start_render_thread(device='auto'):
         rthread.daemon = True
         rthread.name = THREAD_NAME_PREFIX + device
         rthread.start()
+        timeout = LOCK_TIMEOUT
+        while not rthread.is_alive():
+            if timeout <= 0: raise Exception('render_thread', rthread.name, 'failed to start before timeout or has crashed.')
+            timeout -= 1
+            time.sleep(1)
         render_threads.append(rthread)
     finally:
         manager_lock.release()
diff --git a/ui/server.py b/ui/server.py
index 68d22ac5..2d7f7bd8 100644
--- a/ui/server.py
+++ b/ui/server.py
@@ -1,3 +1,7 @@
+"""server.py: FastAPI SD-UI Web Host.
+Notes:
+    async endpoints always run on the main thread. Without they run on the thread pool.
+"""
 import json
 import traceback
 
@@ -343,7 +347,7 @@ config = getConfig()
 
 async def check_status(): # Task to Validate user config shortly after startup.
     # Check that the loaded config.json yielded a server in a known valid state.
-    # Issues found, try to fix and warn the user.
+    # When issues are found, try to fix them when possible and warn the user.
     device_count = 0
     for i in range(10): # Wait for devices to register and/or change names.
         await asyncio.sleep(3)