Yes, 'R600' is here. AMD today launched the delayed next-gen graphics chip, offering both desktop and mobile versions of the DirectX 10-ready GPU.

The desktop line-up comprises the $399 ATI Radeon HD 2900 XT - it's less than half the price of arch-rival Nvidia's top-of-the-line GPU, the GeForce 8800 Ultra - and the mid-range and low-end 2600 and 2400 series.

The 2400 contain 180m transistors, many of which form the chip's 40 unified shader processors and its 64-bit DDR 2/GDDR 3 memory controller. The 2600 core has a 128-bit memory interface - with GDDR 4 support too - and 120 shaders. It's made out of 390m transistors.

Some 700m 80nm transistors go into each 2900 XT, which contains 320 unified shaders and a 512-bit GDDR 4/GDDR 4 memory link.

The 740MHz 2900 XT is available from today, but 2400- and 2600-class parts won't hit the shops until late June.

Notebook-oriented Radeon HD 2000 series chips will appear sooner - later this month, in fact. Coming to market as the Mobility Radeon HD 2600 series, the GPUs will be pitched at mainstream notebooks. AMD will also offer the Mobility Radeon HD 2400 series, aimed at thin'n'light laptops. Like the desktop versions, the laptop chips are being pitched - as are Nvidia's - as the ideal foundations for HD DVD and Blu-ray Disc playback.

Desktop and notebook chips will appear in products from all the usual PC maker and add-in card manufacturer suspects.