It's been less than a week since ATI's mainstream DirectX 10 cards, the Radeon HD 2400 and 2600 series were released into the wild (at least for reviewers) and sadly for the beleaguered company, the new products are unlikely to set any performance records in their respective segments. Although we have yet to get our hands on the top Radeon HD 2600 card, the XT, the reviews so far have shown it falling short of the NVIDIA's top mainstream contender, the GeForce 8600 GTS.
Realizing its precarious situation, ATI has moved to revise its recommended retail prices for the new cards. The Radeon HD 2600 XT was initially priced at US$199 in the presentations given by ATI during the May launch of the high-end Radeon HD 2900 XT but in the latest press release announcing the Radeon HD 2400 and 2600 series, that has been lowered significantly to US$149. Similarly, the other lesser models in the series have also undergone price cuts to make it more competitive against the corresponding NVIDIA counterpart. This strategy has been used before by ATI for its Radeon HD 2900 XT and for the case of these new mainstream cards, positions them on a slightly lower bracket in both performance and price to NVIDIA, hence dodging a potentially damaging, direct confrontation.
Since we have already seen the budget Radeon HD 2400 series in action with this review of the Radeon HD 2400 XT card, it is now time to take a closer look at the Radeon HD 2600 series. Unfortunately, our Radeon HD 2600 XT card came too late to be included in this article so we'll only have a Radeon HD 2600 PRO from Sapphire for our benchmarks. This is not the reference version as the core and memory clocks on the Sapphire have been raised, making this an overclocked card out-of-the-box that should be faster (and probably more costly) than the standard.
Like the Radeon HD 2400, the 2600 series is manufactured using the 65G+ process technology (basically 65nm process), allowing ATI to squeeze almost 400 million transistors onto a core (RV630) measuring roughly 14mm in width. The die shrink has also allowed for lower power consumption, with the Radeon HD 2600 rated at around 45W by ATI and despite its heavy transistor count (at least 100 million higher than NVIDIA's GeForce 8600 and 8500), temperatures should be relatively cool if our experience with the Radeon HD 2400 XT is any gauge.
The basic architecture found on the original R600 (Radeon HD 2900 XT) is retained for the most part, though as usual, the operational hardware units have been reduced in quantity for the lesser Radeon HD 2600. The number of stream processors have been more than halved, with the Radeon HD 2600 equipped with 120 compared to the 320 on the Radeon HD 2900. Unlike the Radeon HD 2400, the ring bus architecture remains on the 2600 but the main memory bus has also been reduced to 128 bits wide, putting it below older Radeon cards like the 256-bit memory bus of the Radeon X1950 series. The key features and the reasons behind the 'HD' in the Radeon HD 2600 series are all accounted for, including the Universal Video Decoder (UVD) hardware that is actually not found on the high-end Radeon HD 2900. A HD audio controller and HDCP support are other essential HD features on these cards. Below is a table listing some of the important specifications of the Radeon HD 2600 PRO and the existing competitors from both ATI and NVIDIA, both new and old.
|GPU/VPU||ATI Radeon HD 2600 PRO 256MB||NVIDIA GeForce 8600 GT 256MB||Radeon X1650 XT 256MB||NVIDIA GeForce 7600 GT 256MB|
|Transistor Count||390 million||289 million||330 million||177 million|
|Manufacturing Process (microns)||0.065||0.08||0.08||0.09|
|Core Clock||600 - 800MHz||540MHz||575MHz||560MHz|
|Vertex Shader Pipelines||24 Shader Processors (consisting of 120 Stream Processing Units in total)||32 Stream Processors||8||5|
|Rendering (Pixel) Pipelines||24||12|
|Shader Processor Clock||600 - 800MHz||1190MHz||575MHz||560MHz|
|Texture Mapping Units (TMU) or Texture Filtering (TF) units||8||16||8||12|
|Raster Operator units (ROP)||4||8||8||8|
|Memory Clock||400 - 500MHz (800 - 1000MHz DDR2/3)||700MHz (1400MHz DDR3)||690MHz (1380MHz DDR3)||700MHz (1400MHz DDR3)|
|DDR Memory Bus||128-bit||128-bit||128-bit||128-bit|
|Memory Bandwidth||12.8 - 16.0GB/s||22.4GB/s||21.6GB/s||22.4GB/s|
|Ring Bus Memory Controller||256-bit (for memory reads only)||NIL||256-bit (for memory reads only)||NIL|
|Molex Power Connectors||NIL||NIL||NIL||NIL|
|Multi GPU Technology||Yes (CrossFire)||Yes (SLI)||Yes (CrossFire)||Yes (SLI)|
|DVI Output Support||2 x Dual-Link||2 x Dual-Link||1 x Dual-Link 1 x Single Link||1 x Dual-Link 1 x Single Link|
|HDCP Compliance||Yes||Vendor Dependant||No||No|
|Estimated Retail Price (US$)||~US$89 - 99||~US$119 - 149||~US$119||~US$99 - 119|