As suggested, in
Administration » Configuration » Development (at
/admin/config/development/logging) you can find the setting to disable displaying of error messages, but it won't disable error/notices completely.
It's because Drupal 7 enforces E_ALL, so they're still written to syslog and you can see them in Recent logs affecting your website performance.
To disable the notices completely, you'll have to add the following line into your
ini_set('error_reporting', E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);
Show all errors, except for notices and coding standards warnings.
To silence all PHP errors, which is not recommended, you may try to addin your settings file:
error_reporting(0); // Disable all errors.
Responsible Drupal 7 core code for
E_ALL logging (file:
// Enforce E_ALL, but allow users to set levels not part of E_ALL.
error_reporting(E_ALL | error_reporting());