Computing and Gaming Hardware revenue increased $3.2 billion or 49%, primarily due to higher revenue from the Xbox Platform and Surface. Xbox Platform revenue increased $1.7 billion or 34%, due mainly to sales of Xbox One, which was released in November 2013, offset in part by a decrease in sales of Xbox 360. We sold 11.7 million Xbox consoles during fiscal year 2014 compared with 9.8 million Xbox consoles during fiscal year 2013. Surface revenue increased $1.3 billion or 157%, due mainly to a higher number of devices and accessories sold.
Computing and Gaming Hardware gross margin decreased slightly, due to a $3.2 billion or 59% increase in cost of revenue, offset in part by higher revenue. Xbox Platform cost of revenue increased $2.1 billion or 72%, due mainly to higher volumes of consoles sold and higher costs associated with Xbox One. Surface cost of revenue increased $970 million or 51%, due mainly to a higher number of devices and accessories sold, offset in part by a charge for Surface RT inventory adjustments of approximately $900 million in fiscal year 2013.