http://blogs.msdn.com/b/msroboticsstudio/archive/2007/10/19/performance-considerations-when-using-enumerable-types.aspxWe’ve observed a high CPU utilization when using enumerable datatypes with binary serialization/intranode interaction. Performance degradation is most noticeable when a List (or Array) contains many items and/or the frequency of use is very high. Theen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)