Operation and performance of CMS silicon tracking detector

The experiments now operating at the CERN Large Hadron Collider all include large, state of the art silicon detector systems for measuring the trajectories of charged particles from the proton-proton collisions. The CMS silicon tracking detector is the largest silicon tracking detector every built, with almost 10 million microstrip sensor elements and 66 million pixels. It has been operating very successfully since collisions began in late 2009 and the performance is very consistent with the design goals. Results from the early operation will be shown and comments made on the challenges of designing and constructing such systems.