After updating the Nexus 5X, Google has now released an update for the flagship Nexus 6P. Like the Nexus 5X update, the 6P update focuses primarily on improving the performance for background and foreground tasks. Google also fixed the 'until next alarm' bug, and there are some carrier-specific updates as well. Overall, nothing major, but if you ever experienced some performance hiccups on your Nexus 6P or any other minor bugs you can expect to see some improvements. Source ...
Source: http://www.gsmarena.com/nexus_6p_gets_performance_boosting_update-news-17150.php