AMD has launched its first complete range of graphics cards since it bought graphics company ATI in July of last year.

The cards are set to compete with Nvidia's GeForce 8000 series, which have a six month lead in the DirectX 10 space.

AMD surprised 150 journalists at the launch in Tunisia by announcing its fastest card, the Radeon HD 2900XT, previously codenamed R600, would only compete with Nvidia's GeForce 8800GTS, indicating Nvidia's 8800GTX will remain the fastest graphics card in the PC space.

Early indications show that despite scoring 17601 in 3DMark05, the highest ever score in our labs, the Radeon HD 2900XT is as fast as the lesser Geforce 8800GTS in real-game performance.

The Radeon HD 2900XT is a 700million transistor graphics processing unit (GPU) built upon an 80nm process with 512MB GDDR3 Ram. A superior 65nm version is rumoured to be in the final stages of development.

The low-end Radeon HD 2400 and mid-range Radeon HD 2600 cards are already based on a 65nm manufacturing process. They will come in Pro and XT editions, with the XT having higher GPU and memory frequencies.

The cards have a lot in common with ATI's Xenos chip used in the Xbox360. Like the Xenos, stream processors are used that are dynamically allocated to perform physics operations or pixel, vertex, or geometry shader operations, the latter of which is new to DirectX10. The Radeon HD 2900XT has 320 shaders running at 740MHz each whereas Nvidia's GeForce 8800GTX has 128 shaders running at 1.35GHz each.

All cards will have HDCP keys onboard and come with an HDMI (1.2 spec) dongle. In another surprise move, AMD announced the cards will have an integrated sound controller, which means the HDMI dongle can output 5.1 surround sound.

Other novel features include tessellation functions being performed in hardware, which means triangles can be split into multiple triangles without a significant performance hit and resulting in a greater level of perceived detail.

AMD has suggested retail prices of €99, €199, €399 for the low, mid and high end cards respectively.

Details of lower powered 'Mobility' versions of the chips for notebooks were also outlined in Tunisia. All cards will go on sale in July, with the exception of the high end Radeon HD 2900XT, which can be bought online today.