In one embodiment, a network recorder includes a storage device; a motherboard; and daughter-cards. Each of the daughter-cards includes an input port, a packet analyzer, an entropy calculator, a comparator, and a processor. The input port receives a plurality of computer data packets. The packet analyzer identifies header fields and a starting point of the payload data in the plurality of computer data packets. The entropy calculator examines the payload data of the plurality of the computer data packets to respectively generate an entropy estimate for each of the plurality of computer data packets. The comparator compares each entropy estimate with an entropy truncation threshold to generate an entropy exceed signal to indicate that the payload data of a computer data packet can be truncated to conserve storage space. The processor compresses at least some of the payload data of the plurality of computer data packets that are not truncated.