ATI R600: the rumours so far

ATI Radeon X2900

It has become clear that the R600 will be sold as the "Radeon X2900". ATI breaks with its own past with this decision: in the last two generations, the first versions of the flagship model were given an 800 name (X800, X1800), and the improved revision of this model was only then labeled with a 9.

The R600 will be completely DirectX 10 compatible, just like its nVidia competion, and will therefore support Shader Model 4.0 and operate internally with unified shaders. The speculation about the amount of shader units and the clock speeds is abundant, and could not be verified. History tells us that the the final clock speeds are only determined at the last minute, right before the launch. What can be verified, is that the R600 consists of well over 700 million transistors, and that it will be manufactured by TSMC in an 80 nm fabrication process.

The Radeon X2900 will be launched in two editions: the Radeon X2900 XTX is the range topper, and it will coexist with a slightly slower (and cheaper!) Radeon X2900 XT. The online rumour mill churns out speculation of a Radeon X2900 XL (an even cheaper version) that will appear later on in its lifetime, as well as a dual core Radeon X2900 XTX2. The coming of these last two seems to be a safe bet, but it remains impossible to verify. Other stories going around mention a Radeon X2900 XTX Uber Edition, that would be equipped with out-of-the-box watercooling.

A leaked photo of one of the R600 "Dragon's Head" cards.

Dragon's Head

ATI is preparing two versions of its Radeon X2900 XTX. One card, codenamed "Dragon's Head" is targeted at OEM suppliers and is an incredible 30.15 cm in length. The version that's designed as a separate product is codenamed "Dragon's Head 2" and is "just" 24.1 cm in length.

Both XTX cards have the same specifications: both versions will get no less than 1 Gigabyte of GDDR4 memory, that's connected to the R600 core by a 512-bit connection. The maximum power consumption (TDP) of both cards has been set by ATI at no less than 280 Watts! To achieve this end, the cards have two auxiliary power connectors: one familiar 6 pin connector and one new 8 pin version. The latter can provide up to 150 Watts, and when this is added to the 75 Watts that the PCI port itseld can provide and the 75 Watts that the 6 pin version can deliver, we arrive at the necessary 280 Watts that are required to power this goliath.

Two supplementary power connectors on the R600, one of which has 8 pins.

Three sources provide the 280-Watt total.

Cat's Eye and UFO

The Radeon X2900 XT is codenamed "Cat's Eye" and is a bit shorter than the XTX version at 21.2 cm. This cheaper version has "just" 512 MB of onboard memory, GDDR3 this time around. This card also has a set TDP of 280 Watts, although this XT version is expected to consume less power than the XTX in practice.

The Radeon X2900 XL is supposedly codenamed UFO. No further specifications are available at this time.

A diagram of the Radeon X2900 XT, codenamed "Cat's Eye"