About on-access scanning best practice
This section contains recommendations to help you get the best from on-access scanning.
We recommend that you use the default on-access scan settings, as they represent the best balance between protecting your computer against threats and overall system performance. For information about the recommended on-access scan settings, see Sophos support knowledgebase article 114345 (http://www.sophos.com/en-us/support/knowledgebase/114345.aspx).