diff --git a/ui/media/js/main.js b/ui/media/js/main.js
index 0f0fbb51..82eda0be 100644
--- a/ui/media/js/main.js
+++ b/ui/media/js/main.js
@@ -803,7 +803,6 @@ function getCurrentUserRequest() {
             height: heightField.value,
             // allow_nsfw: allowNSFWField.checked,
             turbo: turboField.checked,
-            render_device: getCurrentRenderDeviceSelection(),
             use_full_precision: useFullPrecisionField.checked,
             use_stable_diffusion_model: stableDiffusionModelField.value,
             use_vae_model: vaeModelField.value,
@@ -839,19 +838,6 @@ function getCurrentUserRequest() {
     return newTask
 }
 
-function getCurrentRenderDeviceSelection() {
-    let selectedGPUs = $('#use_gpus').val()
-
-    if (useCPUField.checked && !autoPickGPUsField.checked) {
-        return 'cpu'
-    }
-    if (autoPickGPUsField.checked || selectedGPUs.length == 0) {
-        return 'auto'
-    }
-
-    return selectedGPUs.join(',')
-}
-
 function makeImage() {
     if (!isServerAvailable()) {
         alert('The server is not available.')
@@ -1165,6 +1151,19 @@ promptStrengthSlider.addEventListener('input', updatePromptStrength)
 promptStrengthField.addEventListener('input', updatePromptStrengthSlider)
 updatePromptStrength()
 
+function getCurrentRenderDeviceSelection() {
+    let selectedGPUs = $('#use_gpus').val()
+
+    if (useCPUField.checked && !autoPickGPUsField.checked) {
+        return 'cpu'
+    }
+    if (autoPickGPUsField.checked || selectedGPUs.length == 0) {
+        return 'auto'
+    }
+
+    return selectedGPUs.join(',')
+}
+
 useCPUField.addEventListener('click', function() {
     let gpuSettingEntry = getParameterSettingsEntry('use_gpus')
     let autoPickGPUSettingEntry = getParameterSettingsEntry('auto_pick_gpus')
@@ -1184,11 +1183,19 @@ useCPUField.addEventListener('click', function() {
         }
         gpuSettingEntry.style.display = (autoPickGPUsField.checked ? 'none' : '')
     }
+
+    changeAppConfig({
+        'render_devices': getCurrentRenderDeviceSelection()
+    })
 })
 
 useGPUsField.addEventListener('click', function() {
     let selectedGPUs = $('#use_gpus').val()
     autoPickGPUsField.checked = (selectedGPUs.length === 0)
+
+    changeAppConfig({
+        'render_devices': getCurrentRenderDeviceSelection()
+    })
 })
 
 autoPickGPUsField.addEventListener('click', function() {
@@ -1198,6 +1205,10 @@ autoPickGPUsField.addEventListener('click', function() {
 
     let gpuSettingEntry = getParameterSettingsEntry('use_gpus')
     gpuSettingEntry.style.display = (this.checked ? 'none' : '')
+
+    changeAppConfig({
+        'render_devices': getCurrentRenderDeviceSelection()
+    })
 })
 
 async function changeAppConfig(configDelta) {
diff --git a/ui/sd_internal/task_manager.py b/ui/sd_internal/task_manager.py
index a1b70418..4a4faae6 100644
--- a/ui/sd_internal/task_manager.py
+++ b/ui/sd_internal/task_manager.py
@@ -40,7 +40,7 @@ class RenderTask(): # Task with output queue and completion lock.
     def __init__(self, req: Request):
         self.request: Request = req # Initial Request
         self.response: Any = None # Copy of the last reponse
-        self.render_device = None
+        self.render_device = None # Select the task afinity. (Not used to change active devices).
         self.temp_images:list = [None] * req.num_outputs * (1 if req.show_only_filtered_image else 2)
         self.error: Exception = None
         self.lock: threading.Lock = threading.Lock() # Locks at task start and unlocks when task is completed
@@ -72,7 +72,7 @@ class ImageRequest(BaseModel):
     save_to_disk_path: str = None
     turbo: bool = True
     use_cpu: bool = False ##TODO Remove after UI and plugins transition.
-    render_device: str = 'auto'
+    render_device: str = None
     use_full_precision: bool = False
     use_face_correction: str = None # or "GFPGANv1.3"
     use_upscale: str = None # or "RealESRGAN_x4plus" or "RealESRGAN_x4plus_anime_6B"
diff --git a/ui/server.py b/ui/server.py
index e6a0a9f4..04ccec66 100644
--- a/ui/server.py
+++ b/ui/server.py
@@ -161,6 +161,9 @@ async def setAppConfig(req : SetAppConfigRequest):
     config = getConfig()
     if req.update_branch:
         config['update_branch'] = req.update_branch
+    if req.render_devices:
+        config['render_devices'] = req.render_devices
+        update_render_threads_from_request(req.render_devices)
     try:
         setConfig(config)
         return JSONResponse({'status': 'OK'}, headers=NOCACHE_HEADERS)
@@ -287,27 +290,18 @@ def save_render_devices_to_config(render_devices):
 
     setConfig(config)
 
-def update_render_threads_on_request(req : task_manager.ImageRequest):
-    if req.use_cpu:  # TODO Remove after transition.
-        print('WARNING Replace {use_cpu: true} by {render_device: "cpu"}')
-        req.render_device = 'cpu'
-        del req.use_cpu
+def update_render_threads_from_request(render_device):
+    if render_device not in ('cpu', 'auto') and not render_device.startswith('cuda:'):
+        raise HTTPException(status_code=400, detail=f'Invalid render device requested: {render_device}')
 
-    if req.render_device not in ('cpu', 'auto') and not req.render_device.startswith('cuda:'):
-        raise HTTPException(status_code=400, detail=f'Invalid render device requested: {req.render_device}')
-
-    if req.render_device.startswith('cuda:'):
-        req.render_device = req.render_device.split(',')
-
-    save_render_devices_to_config(req.render_device)
-    del req.render_device
+    if render_device.startswith('cuda:'):
+        render_device = render_device.split(',')
 
+    save_render_devices_to_config(render_device)
     update_render_threads()
 
 @app.post('/render')
 def render(req : task_manager.ImageRequest):
-    update_render_threads_on_request(req)
-
     try:
         save_model_to_config(req.use_stable_diffusion_model, req.use_vae_model)
         req.use_stable_diffusion_model = resolve_ckpt_to_use(req.use_stable_diffusion_model)