The following query will provide details of external and internal memory pressure. It will return the data how much portion in the existing memory is assigned to what kind of memory type.
SELECT TYPE, SUM(single_pages_kb) InternalPressure, SUM(multi_pages_kb) ExtermalPressure
GROUP BY TYPE
ORDER BY SUM(single_pages_kb) DESC, SUM(multi_pages_kb) DESC
What is your method to find memory pressure?
Reference: Pinal Dave (http://blog.sqlauthority.com)