ThreadRacer is a simple CPU benchmark utility designed to test the relative performance of CPU cores. Simultaneous Multi-Threading (SMT) for AMD, and Hyper-Threading (HT) on Intel, accelerates processing by sharing select CPU units between two logical cores, or threads. This means that every pair of CPU cores has shared computational units and cache(s). This can impact performance. Threads should be loaded on distinct CPU core sets before their pairs are utilized, something all modern OSes are aware of. In some cases, it is still preferable to manually disable SMT/HT so that threads are forced to execute on more optimal CPU cores. Process Lasso can disable SMT/HT on a per-process basis by using staggered CPU affinities.