HPCWire – NVIDIA debuted its much-talked-about Kepler GPU this week, promising much better performance and energy efficiency than its previous generation Fermi-based products. The first offerings are mid-range graphics cards targeted at the heart of the desktop and notebook market, but the more powerful second-generation Kepler GPU for high performance computing is already in the pipeline.
The two new products introduced this week, the GeForce GTX 680 for desktop systems and the GeForce 600M GPUs for notebooks, are twice as energy efficient as their Fermi-based counterparts, according to NVIDIA. And although they represent more powerful graphics processors than the previous generation, the overriding design theme of the new architecture is performance per watt, rather than performance per square millimeter. According to Sumit Gupta, NVIDIA’s senior director of the Tesla GPU Computing business unit, that’s a fundamental change in the company’s architectural strategy. “This is the first time that power is a higher order concern than area,” he says.
That’s because, like nearly every chipmaker on the planet, NVIDIA’s fastest growing market segment is the mobile and notebook/ultrabook space
In the Fermi version there were only 32 cores per SM. In the Kepler implementation, they reduced the control logic disproportionally and were able to squeeze in 192.
Boosting the core numbers was a no-brainer, given they were moving from the 40nm process technology with Fermi, to the 28nm node for Kepler. In the case of the GeForce GTX 680, for example, there are 1536 cores — three times as many as in the high-end Fermi GPUs, which topped out at 512 cores. At the same time they reduced the clock frequency from 1.5 GHz on the Fermi chip to just a shade over 1 GHz. Although each core is now doing less work, because there are more of them, throughput increases and does so with lower energy consumption.