Consider not setting all rules to act immediately upon receiving and/or sending. Consider changing some to “Scan Messages after a period of time in a folder”. Then select Messages older than 1 hour. This will help distribute the processing load.

You can also set Auto-Mate to Scan messages only when Outlook is minimized if you want so you are not effected while you are interacting with Outlook. 

Also, if the folders you are scanning have 1000's of messages, it will slow performance.