Methods and systems are described to allow for the parallel processing of packets and other subsets of data that are to be delivered in order after the completion of the parallel processing. The methods and systems may process packets and subsets of data that may vary in size by orders of magnitude. The packets may be transmitted and/or received over data transmission networks that may be orders of magnitude faster than the processing speeds of the parallel processors. Entire packets or subsets of data may be allocated to individual processing units without segmenting the packets between the processing units. A count value may be inserted as metadata to received packets in order to indicate a relative order of arrival. The metadata may be utilized by a multiplexor at the output of the parallel processing units in order to maintain in-sequence delivery of the processed packets.