The HD2600XT is the latest addition to Sapphire's Ultimate range of passively-cooled graphics cards and is worth looking at if you are building any sort of media PC, not so much for its gaming performance but because of what's built into the card's hardware.

Aimed at the mainstream market, AMD's HD2600 (RV630) is a cut-down version of the long awaited R600 core, the HD2900, and comes in two main flavours; the HD2600Pro and the faster HD2600XT. The HD2600XT is available with either GDDR3 or GDDR4 memory, but whichever memory option manufacturers use, it runs through a 128-bit memory interface, much reduced from the HD2900's 512-bit bus, as are the 120 Stream processing units.

As the RV630 is built on a 65mn process, it uses less power than its larger sibling so the reference design loses the need for any extra power other than what's supplied by the PCI-E slot. As with all the R6xx series it has CrossFire technology built in the GPU, doing away with the bulky cable arrangement of the first versions of CrossFire and instead using two external bridges which look almost identical to Nvidia's SLI bridge.

Under the skin of Sapphire's Ultimate HD2600XT lies a full height reference design, using 256MB of GDDR3 memory and an 800MHz core engine; the only thing that's changed is the cooling system and the colour of the PCB, in this case blue.

Instead of the normal cooler and fan which covers three quarters of the reference PCB, Sapphire has used the passive heat-pipe system first seen on the X1650 Pro and XT Ultimates. It's a neatly designed system with a small copper and aluminium heat-sink sitting on top of the GPU, with two heat-pipes running from this, around the back of the card to a large, multi-finned cooler. Although large, this cooler still allows you to use the card with even the most outlandish passively-cooled Northbridges seen on motherboards lately.

Because the heatsink on the GPU is so small, the memory chips are left uncovered. But this doesn't cause any problems as the chips are rated at 750MHz (1,500MHz effective) and Sapphire has them running slower, at just 700MHz (1,400MHz effective), allowing them to be used without the need for additional cooling. If you wanted to run the memory at full speed, you might be able to get away with a set of individual passive heat-sinks for the chips, but it may not be worth the risk for just an additional 50MHz.

Performance-wise, Sapphire's HD2600XT Ultimate runs slower than its standard HD2600XT, but not by much. It scores 9,500 in 3DMark05 and 5,714 in 3DMark06 when tested at a 1,024 by 768 pixel resolution. But performance soon tails off as you add Anti-Aliasing and Anisotropic Filtering, so when tested at a 1,280 x 1,024 pixel resolution with these switched on, the 3Dmark05 score drops to 5,000 while the 3DM06 score drops to just under 3,000.

But you wouldn't buy the HD2600XT Ultimate for its graphics performance; of much more interest is the hardware AMD has added to the HD2xxx series, namely a built-in audio controller and a UVD (Unified Video Decoder).

The UVD handles all the HD-DVD or Blu-ray decoding duties, relieving both the GPU and the system CPU of the job, which speeds things up nicely. The 5.1-channel audio controller built into the GPU uses the audio codec in the motherboard but accesses it by the system bus, doing away with the need for any cabling.

The backplate of the card doesn't feature an HDMI port, just the usual suspects; two DVI and an S-Video port. But Sapphire has come up trumps when it comes to outputting HD content to your TV, supplying a DVI/HDMI adapter with the card; and this is no ordinary adapter as it carries both video AND audio signals out to your screen.

Sapphire's HD2600XT Ultimate is definitely a card to think about if you are building an HTPC, with its mix of silence and onboard features, the only drawback being it's a full-sized card so not one for the smaller case. The price tag's not too bad either.