AMD's family of new DirectX 10 graphics cards is comprised of three new SKU's, the R600, RV630, and RV610. We first looked into the R600 at launch back in May as the Radeon HD 2900 XT and covered the basics of AMD's DirectX 10 technology. The two new chips with we're looking at today are based on the R600, using the same internal logic but scaled back with less internal parallelism to make them smaller and less expensive cheaper cores. The RV610 and RV630 share the R600's unified shader architecture, which dynamically deploys on-chip computational resources to address the most pressing graphics problem at hand for pixel shading or vertex processing and manipulation. - Legit Reviews

ATI Radeon HD 2400 XT, HD 2600 PRO and XT Review

Beyond the 3D graphics stuff, these new GPU's pack in some HD video playback capabilities that are not present in Radeon HD 2900 XT. The new video playback features are touted as Avivo HD. The most prominent of them is dubbed UVD, for Universal Video Decoder. UVD handles key portions of the decoding process for High Definition codecs like H.264 and VC-1, lowering the CPU usage during playback of HD DVD and Blu-ray movies. These lower-end Radeon HD 2000 series also feature hardware acceleration of deinterlacing, vertical and horizontal scaling, and color correction.

The Radeon HD 2400 XT video card is quite a strange looking graphics card, with an odd shape. The heatsink is tiny and doesn't make much noise at all. There is no additional PCI Express power connectors required and the card runs nice and cool. On the backside of the card we can see a pair of memory IC's and the heatsink retention bracket. The memory on our Radeon HD 2400 XT is supplied by Hynix. From their decoder we are able to figure out that it's 256MB of 900MHz GDDR3 memory. Current pricing puts this card right around $80 which is a pretty good deal for the DirectX 10 and HD Avivo support

Our Radeon HD 2600 PRO comes in the same size and look of the Radeon X1600 video cards of last generation. We see the same heatsink carried over from the Radoen HD 2400 XT on the Radeon HD 2600 PRO. The Radeon HD 2600 PRO comes clocked at 600MHz core clock speed and 500MHz memory. So while it's clocked lower than the Radeon HD 2400 XT it's using the same larger, more powerful core of the Radeon HD 2600 XT and may be the best value for those looking to do some overclocking. On the backside there are four Qimonda memory IC's, good for 256MB of GDDR3 memory.

The Radeon HD 2600 XT has a similar heatsink, size, and layout to the Radeon X1900 PRO, although the flames on the heatsink are new. One welcome change is that the Radeon HD 2600 XT does not require a PCI Express connector. You can find the Radeon HD 2600 XT priced around $108. At 800MHz the core speed of the Radeon HD 2600 XT is one of the highest we've seen yet out of a video card, this is one of the great advantages to the 65nm process. The memory speed clocks on the Radeon 2600 XT are 1600MHz for the GDDR3 models and 2200MHz for the GDDR4 variant, just like our card.

With the future of gaming still on hold for the most part, pending games like Crysis and Alan Wake that promise to knock your socks off, it's hard to recommend that anyone buy a DirectX 10 video card solely for that particular functionality at this point. Rumors are swirling about new high-end video cards from NVIDIA later this year, which will undoubtedly drop the prices on the current GeForce 8800 series and Radeon HD 2900 XT so our recommendation is to wait. ATI's low cost and low power DirectX 10 solutions have arrived. With a great list of features including hardware HD video decoding.