A Turbo Card, also known as an accelerator card, is a hardware expansion that upgrades the Amiga's CPU to a faster processor, typically fitting into the trapdoor slot beneath the Amiga 500 or 2000. These cards often included additional Fast RAM and sometimes a real-time clock, dramatically improving system performance for CPU-intensive tasks like 3D rendering and compilation. Popular examples include the Commodore A2630 and various third-party accelerators from companies like GVP and Phase5.