A method, apparatus, and computer instructions for transferring data from a memory to a network adapter in a data processing system. The frame size for a transfer of the data from the memory to the network adapter is identified. If the frame size is divisible by a cache line size without a remainder, a valid data length is set equal to the length field. However, if the frame size divided by the cache line size results in a remainder, the length field is set to align the data with the cache line size. The data transfer is then initiated using these fields.