ATI's much delayed R600 core and architecture initially failed to convince critics and consumers when it was finally released last year but the company has moved quickly to shrinking the core to 55nm, which resulted in the Radeon HD 3000 series merely six months after the R600's debut. While ATI still had to concede the high-end to NVIDIA, it did slow the worrying erosion of ATI's market share. In fact, the graphics division was doing fairly well as opposed to the company's CPU business.
Early this year, this relatively successful die shrink was extended to the lower and mainstream segments. Christened the Radeon HD 3600 and 3400 series, these new graphics cards are basically 55nm refreshes of the Radeon HD 2600 and 2400 series respectively, with updated specifications that support the latest standards being pushed aggressively by ATI as a way to distinguish its products from its competitor, like Shader Model 4.1 and DirectX 10.1 support . They are also the first ATI products to natively support DisplayPort, the new audio/video display interface that will compete against HDMI. Here's how the newcomers stack up:-
|Model||ATI Radeon HD 3650 512MB||ATI Radeon HD 3850 256MB||NVIDIA GeForce 8600 GTS 256MB||NVIDIA GeForce 8600 GT 256MB||ATI Radeon HD 2600 XT 256MB GDDR4|
|Transistor Count||378 million||666 million||289 million||289 million||390 million|
|Manufacturing Process (microns)||0.055||0.055||0.08||0.08||0.065|
|Stream Processors||24 Shader units consisting of 120 Stream Processors||64 Shader units consisting of 320 Stream Processors||32 Stream Processors||32 Stream Processors||24 Shader units consisting of 120 Stream Processors|
|Stream Processor Clock||725MHz||670MHz||1450MHz||1190MHz||800MHz|
|Texture Mapping Units (TMU) or Texture Filtering (TF) units||8||16||16||16||8|
|Raster Operator units (ROP)||4||16||8||8||4|
|Memory Clock||1000 - 1600MHz DDR2/3||1660MHz DDR3||2000MHz DDR3||1400MHz GDDR3||2200MHz DDR4|
|DDR Memory Bus||128-bit||256-bit||128-bit||128-bit||128-bit|
|Memory Bandwidth||up to 25.6GB/s||53.1GB/s||32.0GB/s||22.4GB/s||35.2GB/s|
|Ring Bus Memory Controller||256-bit (for memory reads only)||512-bit||NIL||NIL||256-bit (for memory reads only)|
|PCI Express Interface||PCIe ver 2.0 x16||PCIe ver 2.0 x16||x16||x16||x16|
|Molex Power Connectors||No||Yes||Yes||No||Yes|
|Multi GPU Technology||Yes (CrossFire)||Yes (CrossFire)||Yes (SLI)||Yes (SLI)||Yes (CrossFire)|
|DVI Output Support||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link|
|HDCP Output Cable?||Yes||Yes||Yes||Vendor dependent||Yes|
|Street Price||~US$90 - 109||~US$149 - 169||~US$109 - 149||~US$90 - 120||~US$90 - 109|
As you can see from the specifications, the Radeon HD 3650 is exactly like the Radeon HD 2600 XT in terms of its hardware, with the same number of unified shaders and ROPs. The limitations of the older chipset are also evident, like the 128-bit memory bus. On the plus side, the die shrink means there's no longer a need for a power connector due to its lower power draw and in the same vein, ATI's power saving technology, PowerPlay is also present to reduce power consumption during idle. ATI has managed to optimize the core, leading to a slightly smaller transistor count of 378 million. Finally, there's PCIe 2.0 x16 support, making it suitable for newer motherboards, along with CrossFireX support, allowing it to be linked to multiple ATI GPUs of differing speeds.
However, given the similarities in hardware processing power between the Radeon HD 2600 and 3600 series, the lower clock speed of the Radeon HD 3650 does seem to hint that ATI is not that concerned with the performance. Instead, this new SKU appears to be about updating features and bringing the company's mainstream products in line with its existing Radeon HD 3800 series. Are the lower clocks going to severely hurt this SKU? To find out, we'll be looking at a Radeon HD 3650 graphics card from MSI.