Radeon Hard disk 6900 Series Upgrades

The high-end "Cayman" architecture used by the Radeon HD 6900 series is a little different to that of the Barts, which debuted with the Radeon Hard disk 6870 and HD 6850 graphics cards.

The Barts variant used the same VLIW5 configuration as the Radeon HD 5000 series, which features SIMD units with four simple and 1 complex stream processing unit.

The Radeon HD 6900 serial on the other manus adopts a VLIW4 configuration, which features stream processing units bundled in groups of four along with general purpose registers. Although the four accept equal capabilities, two out of four of these (occupying three and iv issue slots) are assigned with some special functions. AMD claims that VLIW4 configuration gives similar computational power as VLIW5, with x% reduction in dice area.

The Cayman GPUs feature a greater level of parallelization when compared to the Evergreen/Cypress architecture used past the Radeon Hard disk drive 5800 series. The Barts GPUs sit down somewhere in the centre, as they were a step upward from Cypress in assigning private dispatch processors for each of the two SIMD Engine blocks.

The Cayman GPUs accept things a footstep further with dual GPEs (Graphics Processing Engines) and assigning each to an SIMD engine block. What this ways is that the Cayman architecture* at present features two physical tessellation units whereas Barts merely featured a unmarried tessellation unit with improved efficiency when compared to the Radeon Hard disk 5800 series as claimed by AMD.

What this ways for the Radeon HD 6900 series is that tessellation operation can be improved quite significantly. In fact, AMD is claiming up to 3x the performance of the Radeon HD 5870 in these scenarios, which as you might retrieve were the ones Nvidia liked to point out when claiming Fermi was architecturally superior than previous-generation Radeons.

In add-on, the Cayman architecture also features reworked render backends consisting of 128 Z/Stencil ROPs, and 32 color ROPs, with up to 2x faster 16-flake integer operations and 2-4x faster 32-bit floating indicate operations.

Notation: For sake of simplicity nosotros have referred to Cayman and Barts code-names that identify the high-end and mid-range desktop products in the AMD's latest 6000-series GPU family (code-named every bit a whole "Northern Islands").