When AMD's Mantle API was announced just over a month ago, PC gamers were excited about the performance improvements it would bring to those with a Graphics Core Next-based AMD GPU. However at the time, only one developer, EA DICE, was announced to be working with AMD on producing a game that uses Mantle; that game being the Frostbite 3-powered Battlefield 4.

Today, AMD announced that three more developers are working on incorporating Mantle into their upcoming games. First up, Square Enix's Eidos-Montréal studio has partnered with AMD for Mantle in future titles, including its upcoming game Thief, which is set for release in February 2014.

Cloud Imperium Games, currently working on the crowd-funded Star Citizen, is the second developer to partner with AMD. Chris Roberts, CEO at the studio, said that "Mantle is vitally important for a game like Star Citizen, which is being designed with the need for massive GPU horsepower", indicating that AMD and the studio have modified Crytek's fourth-gen CryEngine to make use of the API in this game.

The final developer to join the Mantle bandwagon is Oxide Games, who are currently developing a new 64-bit, multi-platform, multi-core game engine called 'Nitrous'. The engine is in the early stages of development, so on release, it should be optimized fully for Mantle.

Mantle is AMD's PC-specific, low-level graphics API which will allow developers to get closer to the GPU's 'metal' to bring out the best performance, similar to what is seen in the consoles. AMD claims the API can facilitate nine times more draw calls per second than other APIs, which is an impressive feat.

With today's announcement, four studios will be incorporating Mantle into their games, and two engines are known to support the API (Frostbite and Nitrous). Big name studios such as Ubisoft (for the Dunia, Disrupt and Anvil engines), Epic Games (Unreal Engine), Crytek (CryEngine), Valve (Source) and Rockstar Games (RAGE) are yet to throw their support behind Mantle, but AMD assures us that more developers will team up in due course.