This new Sapphire card is based on the Radeon HD 2900XT, which is AMD's first major graphics card launch since the company bought ATI last year.

It was initially set to launch at the same time as Nvidia's high-end Geforce 8800 series back in November 2006.

Since AMD recently announced the card would only compete with the 8800GTS and not Nvidia's fastest 8800GTX, it's something of a humiliating blow for AMD.

The Radeon HD 2900XT features a 700 million transistor graphics processing unit (GPU) built on an 80nm process with 512MB GDDR3 Ram. A higher clocked 2900XTX version with 1GB of DDR4 Ram will supposedly be made available to manufacturers, however, it costs a lot more to make and has almost identical performance to the 2900XT tested here.

The Radeon range now sports an HD badge since all the cards will have HDCP keys onboard and come with an HDMI dongle. This means they are perfect for hooking up to an HD TV for playback of Blu-ray or HD-DVD movies.

What's more, AMD has fitted each GPU with an integrated sound controller. Since the audio is routed across the PCI Express bus, the 5.1 surround sound can be neatly outputted through the HDMI dongle.

In practice, you still need a sound card (such as Creative's X-Fi range or an integrated sound chip) to handle the audio. Since the HDMI is only the 1.2 specification and not the most recent 1.3 version you don't get 7.1 surround sound support, Deep Colour, Dolby TrueHD or DTS-HD audio formats.

Some Nvidia cards also support HDMI with audio output, but they require an SPDIF connection direct from the sound card.

These new Radeon cards have a lot in common with ATI's Xenos chip used in the Xbox360. As with the Xenos, stream processors are used and are dynamically allocated to perform pixel, vertex and geometry shader operations as well as physics operations.

Another novel feature the Radeon HD packs is a hardware tessellation chip. This chip splits triangles into multiple triangles resulting in a greater level of perceived detail, without a significant performance hit; this is a feature to watch out for in the future, since games need to be optimised for it.

Sapphire's card is based on AMD's reference design. At 23.8cm it's slightly longer than the 8800GTS, but not quite as long as the 8800GTX. The core runs at 740MHz and there's 512MB DDR3 Ram running at 1650MHz.