Has anyone noticed whether or not the delta discoveries are more or less resource intensive than the full discoveries? Right now we're running AD System Group Discovery every 4 hours, and I'm curious as to whether or not turning on Delta Discovery at an interval of 60 minutes would cause more resource drain on the server than 1 full discovery every 4 hours.

Well it's "full vs delta" ... it depends on the number of objects that have changed.

As Torsten said, it partially depends on the number of new objects discovered. Delta Discovery does not scan the entire AD directory, it uses a "version" number of sorts (the USN) in AD that allows it to retrieve only the new or changed objects. The impact on AD/DC is minimal and the impact on ConfigMgr dpends entirely on the number of changes. I recall reading that internal Microsoft IT changed their schedule to only do a full discovery every 7 days (or something like that) with Delta Discovery running every 5 minutes.Jason | http://myitforum.com/cs2/blogs/jsandys | http://blogs.catapultsystems.com/jsandys/default.aspx | Twitter @JasonSandys