Amdahl's law says that the overall speedup from improving one part of a system is capped by how much of the work that part handles. If a program spends 90 percent of its time on a task that you make infinitely fast, the whole program can at most become ten times faster, because the remaining 10 percent still takes the same time. The unimproved part becomes the bottleneck. Gene Amdahl presented the idea in 1967 at a major computing conference, in an argument about the limits of parallel processors. It is why adding more processor cores eventually stops helping: the parts of a job that must run one step after another set the ceiling. The law applies to any system, not just computers.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.