TOPS counts how many trillion basic calculations a chip can perform each second, usually on small low-precision numbers. It is most often quoted for NPUs, the AI engines inside laptops and phones.
Treat it as a ceiling, not a speed test: the figure depends on the number format used, and real AI work is often limited by memory rather than arithmetic. Microsoft’s Copilot+ PC specification, for example, requires an NPU rated at 40 TOPS or more.