updated 10:00 am EDT, Thu March 22, 2012
NVIDIA GeForce 600 Kepler graphics official
NVIDIA formally brought its Kepler graphics core to the market Thursday, starting with its desktop line. The GeForce GTX 680 introduces new multiprocessing core groups known as SMX; they reportedly provide twice as much performance for the same energy as the GeForce 500 series. With three times as many cores as its ancestor (1,536), 2GB of 256-bit GDDR5 memory, and a 1GHz base clock, it's purportedly 43 percent faster in a game like Skyrim than AMD's Radeon HD 7970, even as it uses 28 percent less power.
The GTX 680 introduces several new tricks to maximize its performance. Many of the power savings come from jumping from 40-nanometer manufacturing to a smaller, cooler-running 28-nanometer process. GPU Boost gives it a mild amount of dynamic overclocking like Intel chips, boosting it up to 1.06GHz when a game doesn't fully tax the processing cores. VSync is also adaptive rather than fixed, and both the recently leaked TXAA antialiasing and a new FXAA mode help clean the image without knocking the frame rate too severely.
The board itself is designed to be much better-behaved under load, using dampeners, more efficient heat pipes, and new heat sinks to keep it quieter. A reduced overall power requirement of 195W also puts less strain on the system itself.
A GTX 680 can handle as many as four displays, three of them in 3D Vision Surround mode, as well as full DirectX 11.1 (and OpenGL 4) visual effects. General-purpose computing should also benefit, although some of the most advanced features are being showcased in PhysX. Its physics engine can now dynamically shatter objects and model as many as 100,000 active hairs.
A reference design is PCIe 3.0-capable and has two dual-link DVI outputs, one DisplayPort, and one HDMI. Boards are shipping from ASUS, EVGA, MSI, and others at a lower price than some had expected, at $499. Whole computers should get the design as well, and leaks have suggested either the 680 or a close variant could reach Apple's Mac Pro, at least as a high-end option.