Abstract: Hardware only transmission control protocol segmentation for a high performance network interface card. Specifically, one embodiment of the present invention includes a circuit for implementing transmission control protocol (TCP) segmentation. The circuit includes a segmentation circuit coupled to receive a descriptor from a host device which corresponds to data. The segmentation circuit utilizes the descriptor to generate other descriptors that describe each frame segment. Furthermore, the circuit also includes a data download circuit coupled to the segmentation circuit to receive the frame segment descriptors. Specifically, the data download circuit retrieves the data from a memory. Moreover, the circuit includes a medium access control circuit coupled to the data download circuit to receive the data in a frame segment.