• Features at a glance
• Superscale unified Shader architecture
• PCI Express 2.0 support
• 320 Unified Stream Processors
• 256-bit memory interface
• Direct X 10.1 / Shader Model 4.1 / OpenGL 2.0
• ATI Crossfire X Multi-GPU Support for highly scalable performance
• Up to four GPU support with an AMD 790FX based motherboard
• High-speed 128-bit-HDR (High Dynamic Range) rendering
• Up to 24x Custom Filter Anti-Aliasing
• 55nm process technology
• ATI Avivo HD Video and Display Technology
• Game Physics processing capability
• Up to 24X Custom Filter Anti-Aliasing
• Built-in HDMI with Multi-channel 5.1 surround audio
• Support for the ATI Radeon DVI to HDMI adapter
• Unified Video Deoder (UVD) for Blu-ray and HD DVD
• ATI PowerPlay energy conserving technology
• RoHS compliant
• Build in HDCP Support
• Windows Vista™ 3D environment Support
• Optimized for Windows Vista™ with comprehensive DirectX® 10 and DirectX® 9 support
• ATI Avivo™ HD Video and Display Technology
• Built-in HDMI with Multi-channel 5.1 surround audio
• Two Dual Link DVI with full resolution HDCP support
• HD video playback
• Full 30-bit display processing
• CATALYST Software Drivers
• Windows Vista™ 3D environment Support
• Support ATI Radeon™ DVI-I to HDMI adapter

The key features of AMD's HD3850 and 3870 cards are identical as they are in fact the same graphics chip with a lower clock speed. DirectX 10.1 is the latest iteration of DirectX including support for Shader Model 4.1 and new anti-aliasing capabilities not found on earlier DirectX's but will probably not affect gamers much as games are mostly released to support DX9 or 10 and the development period. Games are now being released to support DirectX 10, including Crysis, Lost Planet and Bioshock but the totality of the installed base for DX10.1 will likely remain small for some time, as early AMD GPUs only supported SM4.0.

The 3850 is based upon ATI's RV670 chip which is built on TSMC's 55 nanometer design and has 666 million transistors on a 192mm2 die. The RV670 has 320 Stream Processors, the same number as on their earlier Radeon 2900XT. There is a 256-bit memory bus on the card allowing for the HD3850 to have a memory bandwidth of 52.8GB/second.

A key feature of the RV670 chip is the ability to do cube map arrays in hardware for the first time. DirectX 10.1 hardware allows developers to use Cube Map Arrays and geometry shaders to do efficient real-time global illumination for the first time by providing a means to calculate the lighting and shadowing required for a scene with thousands of objects. ATI uses a PingPong demo to show this off by showing light reflected and bounced off thousands of balls.

Another new possibility in DirectX 10.1 is the ability to do Ambient Occlusion. Ambient Occlusion is the ability to determine how much light reaches a given surface and how much does not due to an object being in the way. If a ray of light reaches a surface such as the floor, or wall in a game, then that ray increases the amount of light of the surface. A ray of light hitting another object would not increase the light on that surface providing better shadows. The 3xxx series is the first graphics chipset on the planet to support double precision. The 3850 can do 128-bit floating point calculations High Dynamic Range rendering, meaning that the lights can be lighter and the darks darker in a 3D scene. ATI's Crossfire X was announced with their AMD 790X platform in November 2007. This allows the end-user to use up to 4 ATI cards in Crossfire mode via a top connector. ATI claims that up to a 3.2x increase in performance is possible with CrossfireX (4 cards), but we haven't had four cards to test that theory out yet. It should be interesting to see how four cards compare to two (SLI or Crossfire).