The pebibyte per second is a multiple of the unit bit for Data Transfer Rate. The prefix pebi (symbol Pi) is defined in the International System of Units (SI) as a multiplier of 250 (1 pebi, short scale), and therefore 1 pebibyte per second = 250 bytes per second = 1125899906842624 bytes per second. The pebibyte per second has the unit symbol PiB/s.
kibibyte per second
The kibibyte is a the unit of data transfer rate. The binary prefix kibi means 210, or 1024; therefore, 1 kibibyte per second is 1024 bytes per second. The unit symbol for the kibibyte per second is KiB / s.