The Radeon 6900 series was originally designed for the 32nm node, but problems at TSMC forced the cancellation of the plans and a quick backport of the design for 40nm design rules. Cayman chips consist of 2.64 billion transistors and measure 389 mm2. Part of the reason for the larger size is the new eighth generation tesellator which will improve DirectX 11 performance.New Morphological Anti-Aliasing (MAA) and Enhanced Quality Anti-Aliasing (EQAA) modes have also been added. MAA is a post-process filtering technique that is accelerated with DirectCompute. It delivers full-scene anti-aliasing and is not limited to polygon edges or alpha-tested surfaces.The big difference in the 6900 series is that the cards can by limited by Thermal Design Power using AMD's PowerTune technology, rather than be limited by clock speed as had been done previously. The engine and memory clocks will be dynamically adjusted to fit within the TDP limit of each card. The Radeon HD 6970 can be set to a maximum TDP of 250W while its less powerful sibling will be limited to 200W. Idle power for both is relatively low at 20W. The Radeon HD 6950 requires two 6-pin plugs, but the Radeon HD 6970 will require an 8-pin plug and a 6-pin plug. A BIOS switch has also been added to reset to the default BIOS in case of problems with tweaking.Vapor Chamber Cooling has been relatively rare, but AMD is using it for the reference card design that most Add-In-Board partners will adopt. Vapor chamber coolers are more efficient than traditional heatpipes and easier to design as there are no routing concerns. Chief competitor NVIDIA's high-end GeForce GTX 580 also uses Vapor Chamber Cooling.Both cards have 2 DVI slots, an HDMI 1.4a slot, and 2 mini-DisplayPorts. Four monitors can be supported natively, but up to six monitors can be supported if DisplayPort hubs are used. Support for DisplayPort 1.2 has been added, allowing for a bandwidth of 21.6 Gbps each. DisplayPort hubs are able to tap into this bandwidth using a technology called Multi Stream Transport (MST) and split it for multiple monitors.
The new cards are meant to replace the Radeon HD 5800 series, one of the company's most successful video cards in its history. It was the first to support DirectX 11, but has now been deemed to costly to produce and is being phased out. The Radeon HD 6700 series recently launched offers similar performance to the 5800 series but at a much lower price. The Radeon HD 6970 will generally provide 20% better performance than a Radeon HD 5870 for only $20 more.
The Radeon HD 6990 codenamed Antilles will launch next month. A dual GPU version of the Radeon HD 6970, it is expected to have 4GB of GDDR5 memory.
NVIDIA GTX 580
AMD Radeon HD 6970
NVIDIA GTX 570
AMD Radeon HD 6950
AMD Radeon HD 6870
AMD Radeon HD 5870
1.0GHz (4.0GHz effective) GDDR5
1.375GHz (5.5GHz effective) GDDR5
950MHz (3.8GHz effective) GDDR5
1.25GHz (5.0GHz effective) GDDR5
1.05GHz (4.2GHz effective) GDDR5
1.2GHz (4.8GHz effective) GDDR5
Memory Bus Width
quote: Plus a $25.00 DP to VGA adapter.
quote: It's all a matter of perception really. Some people tolerate low FPS better than others. Plus, you can't go higher than 60 on a LCD anyway.
quote: Nvidia might have won this round in performance