DigiTimes reports the reason why the GeForce GTX 400 series will have fewer cores than originally expected is because TSMC's 40nm yield currently is still under 50 percent.
Since TSMC's 40nm yield currently is still lower than 50%, Nvidia will block some of the graphics cores with problems on the card. As a result, the GeForce GTX 480 will only have 480 cores and GTX 470 only 448, the sources noted.
The sources pointed out that Nvidia will start selling its GeForce GTX 400 series on March 26, but volume shipments will not start until April 6. The sources also noted that GeForce GTX 480 will be priced at US$499 and GeForce GTX 470 at US$349.