Accelerator cards are specialty expansion cards designed primarily for the acceleration of specialized workloads such as vector processing, artificial intelligence, cryptography, and graphics.

Typically, but not always, accelerator cards make use of custom ASIC chips (known as accelerators) in order to execute such workloads far more efficiently than what a normal general-purpose microprocessor would be capable of. Various FPGA-based accelerator cards also exist allowing the user to implement his own hardware acceleration functions.