The GTX 900 series is based on the new, power efficient 'Maxwell' core that first launched with the GTX 750 Ti. The GTX 980 and GTX 970, however, use the bigger GM204 GPU, with 2048 and 1664 cores respectively.
ASUS has launched Strix GTX 980 and GTX 970 graphics cards, bringing the benefits of a DirectCU II cooler with fatter, 10mm heatpipes, fan shut-off at low temps (0dB fan tech) and the usual DIGI+ VRM and Super Alloy Power upgrades inside. Both are factory overclocked to factory-overclocked at 1279MHz and 1253MHz respectively and are packed with 4GB of 7GHz GDDR5 (effective).
Read the full info in the press release below the pics. We've put the Strix GTX 980 picture gallery over here.