CrossFire is a brand name for multi-GPU solution from ATI Technologies. The technology allows up to four graphics cards to be linked in order to produce single output.

September 27, 2005 the CrossFire system was first introduced. The system required CrossFire-compliant motherboard and pair of ATI Radeon (in that time new) x800s, x850s, x1800s and x1900s.
The cards where divided on "Master" card, the one with proprietary DVI Y-dongle, and the regular card from the same series. DVI Y-dongle serves as the main link between both cards.

Second generation, called CrossFire Xpress 3200, did not need a "master" card. Two normal cards can be run in a Crossfire setup, using the only PCI-E bus for communications. Xpress 3200 had been built for high-speed communication and low-latency between graphics cards.

With the release of the Radeon X1950 Pro, ATI has completely revised CrossFire's connection infrastructure and the CrossFire branding was then changed to "ATI CrossFire X". The updated CrossFire can support for a maximum of four video cards with the 790FX chipset. Improvements where made to ATI's CrossFire connector, now it is a ribbon-like connector, similar to nVidia's SLI bridges. According to internal testing by AMD, the new four cards CrossFire will bring at least 3.2x performance increase in modern games and applications which required massive graphics capabilities.

Introduced in early 2008, latest CrossFire infrastructure also include a dual GPU solution, the Radeon HD 3870 X2 and later in Radeon HD 4870 X2 graphics cards.