AMD launched the Radeon HD 7970 GHz Edition graphics card. In its crosshairs is NVIDIA GeForce GTX 680, and retaking the single-GPU performance crown. The new chip, apart from a fully-configured ASIC, features ≥1000 MHz GPU clock speed.
Unlike what previous reports from various sources in the media have been suggesting, the HD 7970 GHz Edition is not based on a new ASIC, or even a new revision of the existing "Tahiti" one. Instead, it is made from hand-picked (binned) high-performing Tahiti chips, from existing batches. It goes with the internal codename "Tahiti XT2." The chip attains high clock speeds and overclocking headroom purely out of tolerance to higher voltages, or higher quality (low leakage) silicons, which can attain higher clock speeds at typical voltages. Speaking of clock speeds, AMD implemented PowerTune with Boost, a technology that sounds similar to NVIDIA GPU Boost. AMD clocked the HD 7970 GHz Edition at 1000 MHz (core), with 1050 MHz (core Boost). The Boost frequency is active for most applications, although some apps with unreal loads (eg: Furmark) can send the frequency down to 1000 MHz. AMD's Boost technology uses a "predictive" algorithm that takes into account how an application behaves, and how it should tune clock speeds (between Boost, nominal, and throttle p-states), and how the GPU voltage should be adjusted on-the-fly to support the clock speeds. Stability and performance seem to be a greater priority than power draw.
The memory clock of the HD 7970 GHz Edition isn't left untouched, it is stepped up to 1500 MHz,. using the same Hynix-made GDDR5 chips that go into the GeForce GTX 600 series. Thanks to the 384-bit wide memory interface, the card ends up with a memory bandwidth of 288 GB/s. The rest of the component load-out is identical to that of the HD 7970.The 28 nm Tahiti silicon packs 2,048 Graphics CoreNext stream processors, which at the given clock speeds, breaches the 1 TFLOP/s double-precision floating-point performance mark. The chip is armed with 128 TMUs, and 32 ROPs. Like the HD 7970, the new HD 7970 GHz Edition draws power from a combination of 8-pin and 6-pin PCIe power connectors. AMD rates its peak power consumption at 250W, just 49W short of that of the GTX 690. Display outputs include dual-link DVI, HDMI, and a pair of mini-DisplayPort connectors. The card can pair with any three more Tahiti-based ones, in CrossFire configuration (that includes HD 7970 (925 MHz), HD 7950, and even HD 7970 X2).