Sapphire is using ATI's Radeon HD 2600 XT chip, which is a step down from ATI's current flagship, the Radeon HD 2900 XT. It's aimed at mid-range users who want an affordable solution for everyday graphics and a little bit of gaming. The HD 2600 XT GPU is manufactured using a 65-nanometre (nm) fabrication process, which makes it smaller than current high-end chips, allowing it to run cooler and with lower energy consumption. Sapphire's HD 2600 XT is also the first DirectX 10 card we've tested that uses GDDR4 memory as opposed to GDDR3, so even though it's a mid-market card, it still boasts high-end tech.
ATI first implemented GDDR4 in its Radeon X1950XTX DirectX 9-based chip and has now brought the technology to its HD 2000-series chips, while Nvidia continues to run on the tried and tested GDDR3. GDDR4 memory offers a fixed burst length of 8-bits rather than 4-bits in GDDR3, so it can produce the same throughput while using half the frequency of a GDDR3 chip. GDDR4 also has a lower power requirement than GDDR3.
Still, it's hardly revolutionary technology and it will only go so far to improve the performance of the card. In the case of the Sapphire HD 2600 XT, we have no direct GDDR3 comparison from ATI. If the HD 2600 XT is aimed at the Nvidia 8600 GT-based (GDDR3) cards, then its performance is all right for its target market. However, even with GDDR4, it's still not as fast as cards based on Nvidia's 8600 GTS chip.
The Sapphire uses 256MB of GDDR4 memory with an effective memory clock speed of 2200MHz, while the core clock speed of the graphics chip is 800MHz. Both these speeds are higher than the HD 2900 XT, but the HD 2600 XT is restricted to 120 stream processors, rather than 320, and the memory bus is 128-bit, unlike the 512-bit memory bus found on the HD 2900 XT.
The Sapphire HD 2600 XT isn't a high-end performer for 3D applications, but it does hold its own and offers other benefits, such as a dedicated video decoder called Universal Video Decode (UVD), which helps take the strain off the CPU when decoding video. This feature is especially useful in PCs that don't have a high-end CPU. In 3DMark06's default test (1280 x 1024, no antialiasing or anisotropic filtering) it scored 5107, while the MSI NX8600GT scored 4495 and the Gigabyte 8600GTS scored 5703, placing it firmly in the middle. At a resolution of 1680 x 1050 with antialiasing cranked up to 8x and anisotropic filtering at 16x, the Sapphire HD 2600 XT scored a lowly 1719.
In FEAR, we ran it at 1280 x 960 using maximum quality settings, including 4x antialiasing and 16x anisotropic filtering, which turned in a poor 25fps. Clearly, if users are after a high-end gaming experience, even on a 19-inch monitor, they'll need to go for one of the more powerful cards.
For users who want a performance boost down the track, it's worth noting that this card supports native CrossFire mode and Sapphire has included a bridging cable in the box. The rear bracket has two DVI outputs and a TV-out port. The box includes two DVI to D-Sub adapters and a component adapter cable, as well as a DVI to HDMI cable with native audio support.
The card operates without excessive noise and, unlike the HD 2900 XT, takes up just one expansion slot with its cooler, rather than imposing on the adjacent slot. No power cable is required as it draws all its power through the PCI Express slot.
While it's not the best performer, the HD 2600 XT is reasonably priced. It doesn't quite stand up to cards that use Nvidia's 8600 GTS chip, but it outperforms the 8600 GT-based cards that we have tested thus far.