6.3.5 Data Tape Performance  Format geometry and dimensions govern performance. Data transfer speed, one aspect of performance, is a direct product of the number of tracks written and read simultaneously, as well as the tape- head speed, linear density and the channel-code. Similarly, physically smaller, lighter tape housings are faster to move in a robotic library. Data density is a product of:  tape length and thickness trade-offs  track width and pitch  linear density of data payload within each track