In the world of smart phones and tablet PCs memory might be cheap, but in the more constrained universe of deeply embedded devices, it is still a precious resource. This is one of the many reasons why most 16- and 32-bit embedded designs rely on the services of a scalable real-time operating system (RTOS). An RTOS allows product designers to focus on the added value of their solution while delegating efficient resource (memory, peripheral, etc.) management. In addition to footprint advantages, an RTOS operates with a degree of determinism that is an essential requirement for a variety of embedded applications. This white paper takes a look at “typical” reported performance metrics for an RTOS in the embedded industry. It’s an attempt to explain what these numbers signify, how they are measured, and why an embedded system designer should give particular attention to these numbers.