Product Reviews

With Windows Vista, DirectX 10 and a glut of next-generation titles on the horizon, it's no surprise there haven't been any major chipset announcements from ATi or Nvidia recently. But with high-definition TFTs and LCD TVs likely to be big sellers over the festive season, HDMI is the one feature that current graphics cards are lacking - though not for much longer. Asus has already told us it intends to give all its graphics cards both HDMI ports and High Definition Content Protection (HDCP), and both MSI and Sapphire are jumping on the bandwagon. Here, we look at four of the first on the market.

HDMI vs DVI

As an all-digital connection, HDMI initially appears very similar to DVI. Bandwidth for both connections is nearly identical: a dual-link DVI connection has a maximum bandwidth of 330MHz, while HDMI is just marginally higher at 340MHz. HDMI supports 48-bit colour depths to DVI's 24-bit, theoretically allowing cards to display billions of colours rather than mere millions. However, when we tested a top-of-the-range HD TV using a DVI output and then an HDMI output, we saw no notable difference in quality - and that's using dedicated testing software. But part of HDMI's appeal to the consumer is its physical simplicity: unlike DVI, there are no screws to fasten, and HDMI looks the part too - it's compact, uncomplicated and will fit into a much smaller space than D-SUB or DVI connectors.

HDMI can carry a digital audio signal as well: up to eight channels of 192kHz surround sound. Graphics cards makers have yet to cotton on to the marketing potential of a graphics card with onboard sound, though, so graphics cards will need to be physically connected to either a sound card or another external source.

Features

All but the MSI NX7600GT Diamond Plus Edition have both internal and external S/PDIF inputs, so you can wire them directly to your motherboard, sound card or even an external source. The Sapphire X1600 Pro and Asus EAX1600PRO both have coaxial inputs on the backplane, while the Asus EN7600GT has an optical connector. To connect an external S/PDIF source to the MSI card, you'll need to take the unorthodox route of running a coaxial cable through the hole in the backplate, and then connecting it internally.

Both 7600s are full-height PCI Express cards, but the X1600

HDCP

Each of these cards has an HDCP chip onboard, but there are few products that will use it yet. Blu-ray and HD DVD movie discs are unlikely to be encrypted for some time, while Sky Plus (which does use HDCP encryption) is incompatible with current versions of Windows XP Media Center Edition.

Performance

Tellingly, all of the cards currently available with HDMI ports are mid-range: two 7600 GTs and two X1600 Pros. With HD TVs rarely exceeding resolutions of 1,920 x 1,080, a higher-end card could arguably be considered a touch gratuitous, but we'd still like the option of a little more fire power - if you do intend to play today's 3D games at 1,980 x 1,020, you'll need more firepower than these cards can provide.

As we'd expect, the 7600-based cards came out on top in terms of performance. In Far Cry, with no anti-aliasing or anisotropic filtering, the Asus and MSI cards scored 38fps and 35fps respectively in our toughest Far Cry test at 1,280 x 1,024, and 15fps each in our equivalent Call of Duty 2 test. The X1600s fared worse, with the Asus scoring 9fps in Call of Duty 2 and 14fps in Far Cry, while the Sapphire scored 21fps in Far Cry and 10fps in Call of Duty 2. These results are slow for modern graphics cards, but there are still plenty of games available that even the X1600 will be able to play.

Pricing

Even considering the annual $10,000 subscription that manufacturers have to pay for HDMI licensing, we were surprised by the price premium attached to each of these cards. The cheaper of the two 7600 GTs, the Asus, costs £27 more than our A-Listed, non-HDMI card version from Inno3D. But things are likely to change soon, with Asus promising HDMI across its entire range of graphics cards, and other manufacturers sure to follow. Prices are likely to come down sooner rather than later.

Conclusion

As with most areas related to HD video, it's far from clear how the market will go. Even if you're using a media centre PC and an HDMI-equipped TV, buying one of these cards isn't a foregone conclusion: DVI-to-HDMI converters are available for around £15, and these will work in the same way as a plain HDMI cable, with the sole current drawback being that they have no audio capabilities. Neither of the X1600 Pro cards here have a DVI port, and we experienced no problems using the HDMI port and a converter to connect to a DVI-I port on a standard TFT. While it will one day be the norm, the extra cost of an HDMI port seems like an expensive extravagance right now; only very early adopters need apply.