petaflop UK /ˈpɛtəflɒp/US /ˈpɛtəflɑp/ noun3 •Either of two units of measure of the calculating speed of a computer. •a quadrillion (10¹⁵) floating point operations per second. •1,125,899,906,842,624 (2⁵⁰) floating point operations per second.First computer to surpass the 1 Petaflop (2⁵⁰ FLOPS) barrier [in 2008] — 2012 formspetaflops