The trials of Monterey
Soon after I start work on my MacBook Pro, it may become unusable for a couple of minutes because of triald. It also has a huge folder named Trial in my Home folder’s Library. What trial is this?
AThese are macOS services new to Big Sur supporting new machine learning features including Siri, Photos face and other recognition, Dictation, Live Text, translation and Visual Look Up. This is centred on triald, a background service to enable models used by those features to be improved without installing a full macOS update.
That folder contains the latest model updates, delivered securely via iCloud. Each day, triald performs routine maintenance on the folder; leave your Mac running through the night and that normally happens in the small hours of the morning. Notebooks and other Macs which are shut down or sleep at that time have to perform this maintenance during the day, and that can use a lot of processor power for a couple of minutes. There’s no control to disable this; even turning Siri off doesn’t stop its model updates from being downloaded and maintenance occurring. Some try deleting the folder, or locking it with root permissions, but that doesn’t seem to help, and can prevent some features from working properly.