Designwise they are about the same as the outgoing 5850 but are considerably cheaper thanks to a shift in architecture.
You can pick up the 6850 for $179 and the 6870 for $239. The beasts are more power efficient, particularly when they are not doing anything.
AMD tells us that it has a performance edge of as much as 30 percent over the GeForce GTX 460.
The chips use DirectX 11 (OpenGL 4.0) graphics and general-purpose DirectCompute or OpenCL. However there are some new ideas including a new morphological antialiasing and improved anisotropic filtering.
Under the bonnet is all the hardware tessellation you can poke a stick at, making it easier to reduce detail for distant objects. The universal video decoder has been sped up to ease the stress on the main processor when you watch HD content.
Most boards will be ready for multi-monitor viewing with dual DVI ports, dual Mini DisplayPorts and an HDMI connector.
Both cards have a 256-bit memory bus and 1GB of GDDR5 RAM. What makes the difference is the number and speed of processing units. The 6850 has 960 stream effects processors, 48 texture units and a 775MHz core clock. A 6870 scales up to 1,120 stream processors, 56 texture units and a 900MHz clock rate.
The cards should already be in the shops. Windows users can choose between boards from Asus, Sapphire, MSI, Diamond, Gigabyte, and XFX.
We are expecting to see a few higher end boards out soon.