Hot on the heels of Nvidia's GTX 570 launch just a week ago, AMD is ready with their answer to the high-end Fermis. The new chip, codenamed Cayman, is finally here and will assume the high-end position in AMD's line up. The new cards are called the HD 6970 and the HD 6950. According to AMD's positioning, we can expect the HD 6970 to replace the HD 5870, whereas the HD 6950 won't replace anything, but rather fill the gap between the HD 6870 and the HD 5870. First, let's talk about what's different in Cayman as compared to AMDs previous Cypress graphics core.
AMD's goal was to build a more efficient graphics and compute architecture, increased geometry performance, add new image quality features and finally improve the power efficiency of these new beasts. To start off, AMD is using a newer VLIW4 architecture, which now houses a dual graphics engine. They have managed to accommodate 24 SIMD engines and up to 96 Texture Units, which when compared to Cypress (HD5870), has 20 SIMD engines and 80 Texture Units.
Due to this, the new architecture allows for up to 10% improvement in performance per mm2. It also gives us a more simplified scheduling and register management due to the extensive logic re-user per clock cycle. Other areas that have improved include the Render Back-ends and GPU Compute, which now feature Asynchronous dispatch.
Another major change is the inclusion of two Graphics Engines. This gives us primitives per clock cycle, which translate to better Tessellation performance as compared to the HD5870. According to AMD, the Tessellation performance is almost three times that of Cypress. There are also new image quality features like Morphological AA, Enhanced Quality AA and Enhanced AF and Texture Filtering. We'll discuss the final power efficiency feature in a bit, but first lets compare the specifications of the cards to get an idea of how different Cayman really is compared to Barts and Cypress.
Cayman has a slightly larger die size with more transistors packed in using the same 40nm fabrication process. The number of stream processors are in fact lesser compared to Cypress, while the ROP's still remain the same. The improved memory configuration allows AMD to really push the speeds higher.
Other common features among AMD's 6000 series (Barts and Cayman and other iterations that may follow) include the following;
AMD HD3D is supported by all 5000 and current 6000 series graphics cards. However, BluRay 3D is only supported in the new 6000 series due to the inclusion of HDMI 1.4a, which is required for playback. Now before you get too excited, the software required to convert your games to 3D is not free (unlike Nvidia that bundles that software with the drivers itself). Two companies offer drivers for AMD HD3D, TriDef 3D and iZ3D.
This is probably the messed up part, because even after paying good money for your graphics card, you have to fork out more just to unlock a feature that's already present. We hope that this is just temporary and AMD is working on drivers of its own to support 3D. Or else it's one feature that most gamers won't bother with or might just go to the green camp if they were looking for a 3D setup.
Since AMD sent us their reference card, there wasn't any bundle.