Modern CPUs provide a wide variety of Single-instruction-multiple-data (SIMD) instructions, or vector instuctions, for operating on larger blocks of data than with regular instructions. Though thought of by many programmers primarily as instructions for doing calculations in parallel on arrays of data, these vector instructions can actually be used in other ways to accelerate packet processing applications. This talk goes through a number of examples in open-source projects, such as DPDK and OVS, where vector instructions have been used to boost performance significantly, and explains the general techniques used that can be applied to other applications.