You may want to completely disable the SNORT configuration to reduce the CPU utilization load. The instructions in this article completely disable SNORT. If you are looking for reducing SNORT memory consumption, please see Configuring SNORT to Reduce Memory Consumption in Kerio Control article.
Note: The linked articles discuss enabling both features, but the exact opposite process (unchecking enable options) can be followed to disable these features.
Also, keep in mind that disabling the Application Awareness will cause some Content Filtering rules to not work. Example: