Not since Winston Churchill flashed his famous 'V for Victory' sign has the single letter 'V' meant so much. In ATI-speak, a GPU part number including 'V' indicates the use of a smaller, more efficient core. In ATI's latest trio of GPUs, therefore, the RV610 (better known as the Radeon HD 2400) and RV630 (aka the Radeon HD 2600) use a smaller production process than the pioneer of the R6xx family, the R600 (the Radeon HD 2900). The HD 2900 uses an 80-nanometer production process, while the HD 2400 and HD 2600 use ATI's new 65-nanometer production process.
Unfortunately for HD 2900 fans, bigger doesn't mean better. The RV610 and 630 may feature smaller memory bus sizes and stream processor counts, but they have one thing their older sibling lacks: GPU accelerated HD video playback . Although ATI's official website for the HD 2900 mentions support for Avivo HD playback, the Daily Tech news site and The Tech Report have discovered that the HD 2900 XT (first of the family) uses CPU-assisted HD playback like older ATI silicon. However, the less powerful HD 2400 and HD 2600 include Avivo HD support in their newly-designed GPUs. Who's to blame for the confusion? ATI. As the Daily Tech and The Tech Report stories show, ATI's pre-launch briefing confused almost everyone.
ATI isn't alone in winding up with a "high-end" chip lacking some features of lower-end GPUs based on newer designs. A recent AnandTech test of NVIDIA and ATI movie playback found that the HD 2600 bested its competition in CPU utilization by a wide margin, including its sibling the HD 2900 XT as well as high-end and mid-range NVIDIA GeForce 8 parts.
ATI often reworks existing designs, and so I'm hoping that eventually some members of the HD 2900 family will wind up using the new 65-nanometer process with its hardware support for HD video playback. For right now, though, ATI provides an unhappy choice: fast 3D gaming performance or low-CPU utilitization HD video playback.