peta- [PE tuh] (Greek: derived from penta-, "five"; a decimal prefix used in the international metric system for measurements).
Used in the metric [decimal] system as one quadrillion [U.S.] or thousand billionfold [U.K.], 1015 [1 000 000 000 000 000] The metric symbol for peta- is P.
1. A unit of computer memory or data storage capacity equal to 1 024 terabytes.
2. One quadrillion bytes. A typewritten page is said to have about 2 000 bytes of data per side; therefore, a megabyte represents a 500 text page per side and a petabyte would be 500 billion pages.
This represents 1 000 (1015) teraflops (floating point operations) per second.
One quadrillion hertz (1015).