Sapphire HD 6990 4GB: Fast and Wild

Finally came a package that we wait for a new graphics card from AMD. It has 2 VGA Cayman XT GPU chipset mounted on a PCB board with the internal chipset AMD CrossFire for later crowned the fastest single VGA unit.

They called this VGA with which no other Antilles islands are in French; Antillas Spain, the Netherlands Antilles and Antilhas in Portuguese) is located in the West Indies in the Caribbean. Whatever that meant AMD code name Antilles, but for the retail version of the market, this VGA will become famous as the HD 6990. That this time it landed in the lab for test trials was beaten Sapphire HD 6990 4GB - AMD reference design.



Two armed Antilles Cayman XT (HD 6970) HD 6990 with detailed specifications:

• 2 x 1536 Stream Processor
• 2 x 32 ROPs
• 2 x 96 TMUs
• 830MHz Core Clock *
• 1250MHz Memory Clock (5000MHz GDDR5 effective)
• 2 x 2GB Memory
• 2 x 256bit memory interface

AMD uses an internal PCI-E CrossFire chip from PLX to facilitate communication between the two cores Cayman XT. PLX chip family tersbut of 8647 with an ultra latency that allows total data communication with 48 channels to improve the previous generation dual GPU monster, HD 5970. SidePort have been eliminated in the Antilles and is now only 7.92 Gbps using a single interconnect.

In theory Antilles architecture, the specification as if it would provide two times faster than the HD 6970 but, because the core clock be set slightly lower (830MHz) than the HD 6970 880MHz clock then there will likely be a bit slower when compared with 2 x HD 6970 CrossFire. Memory speed has also been reduced by 10% which will probably not make much difference because the card is not in the abyss of memory bottleneck.


DUAL BIOS FTW
We like the way AMD is providing the features unlocked anti-830MHz. That this card still holds the potential was taken as corresponding to the specifications in the Cayman XT 880MHz core clock. Apparently AMD has invested two VGA BIOS on this, the BIOS 830 and BIOS 880 (the next one we call "UNLOCKED" or "turbo"). You can activate the BIOS first or second residence near the notch sliding switch on the GPU CrossFire HD 6990 with a recommendation of course when the PC off.