After months of anticipation and many delays, AMD's answer to nVidia's mighty G80 - and the first new product to be launched since AMD's acquisition of ATI - has arrived in the shape of the DirectX 10-supporting R6xx family of cores. The flagship of the HD 2000 range, as the new cards are called, is the HD 2900 XT using the R600 core.

And, as is the norm these days, the HD 2000 family will have lots of members; about ten available now or in the future. At the moment the family tree breaks down like this: 2900 for high end, 2600 for the mainstream, 2400 for the value segment, and not forgetting the mobile part, the 2300 series.

Just as nVidia has done with the G80, AMD has moved to using unified shader architecture in the R600, something that it has had plenty of practice with since ATI supplied the unified shader enhanced Xenon GPU for the Xbox 360. When used in conjunction with unified shader code in DirectX 10, performance is improved. Built on an 80nm process, the R600 has 320 stream processing units which help account for some of the massive 700 million transistor count.

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The architecture also includes new and improved anti-aliasing and texture filters and the latest Avivo technology; Avivo HD. The new Avivo improvements mean that even lower mainstream and value cards can offer HD playback and also transfer audio as well as video through the DVI and HDMI ports. The high end HD 2900 XT has HDCP over Dual-Link DVI and HDMI as well.

Also included is native Crossfire support, meaning you can do away with the bulky Crossfire cable of old. Instead there is a bridging strap that bears a remarkable resemblance to the bridge used by nVidia for SLI systems.

Sapphire's first venture with the HD 2900 XT is, as you might expect, little different from the reference design, indeed the only difference is the stickers on the cooler and fan. On the subject of the fan, there seem to be a lot of complaints being made about how noisy it is, but we were very lucky in having one that - apart from when the system first starts, when it is very loud - is by no means silent but a lot less intrusive than many reports.

The reference theme continues with the core and memory speeds. The core zips along at 740MHz while the 512MB of DDR3 memory is clocked at 825MHz through a 512bit memory bus.

The card features both 8-pin and 6-pin power sockets. Unless you have an ultra brand new power supply, you won't have an 8-pin PCI-E power connector. But fear not: the card will work with two 6-pin connectors (a 550w PSU is advised) although connecting an 8-pin connector is recommended when either setting the cards up in a Crossfire configuration or if you want to get down and dirty with the Overdrive overclocking utility. Disappointingly, Sapphire doesn't supply any 4-pin Molex to 6-pin converters in the box, which would have made life a lot easier.

So is it quick then? Well, yes, and it beats an 8800GTX, but only in the synthetic tests. When tested with 3DMark05 the HD 2900 XT gave a score of 13,011 as opposed to the GTX's 12,534. With the more up-to-date 3DMark06 the tables are turned - just - with a score of 8,300 for the GTX and 8,200 for the XT.

It's a slightly different story when it comes to real world games, with the 8800GTX just out-scoring the HD 2900 XT, e.g. FEAR at 1,280 x 1,024 with all details set to maximum recorded 76.5 for the HD 2900 XT against 86.8 for the 8800GTX.

At last some competition for the G80, and if you are looking to future-proof a system, it's the card to choose with its high clock speeds and programmable filters. It may struggle against the high end nVidia cards but it has a nice trick up its sleeve: it's about £100 cheaper than most 8800GTX cards.