UDP packet reliability

Question

I am trying to write some sample code to test the reliability of receiving UDP packets. Currently I have an application that receives UDP packets, parses out the data, and then inputs that data into an MS access DB. I have some interesting results when I try and run a separate application that sends 200 packets with slightly different information. In this case I get it takes approx. 12,000ms to complete the 200 packet sends. In another case where I disable the receiver from inputting all the data in the DB and just simply receive the packets it takes about 6,500ms to complete. I am wondering, does the receiving end of the UDP system queue up the packets as they come along or if it is bombarded with multiple packets at a time it simply processes them as they come? Can anyone explain how the UDP works in C#. Thanks