AMD reported better-than-expected revenue and earnings for the first quarter, but the stock dropped 6% in extended trading on Tuesday after the chipmaker issued guidance for the current period that falls short of analysts' estimates. The company's client group, which includes sales from PC processors, saw a 65 percent decrease in sales from the same period last year. AMD's data center segment sales increased to $1.295 billion from $1.293 billion during the year-earlier period. Sales in its embedded segment of less powerful chips for networking soared to $1.56 billion from $595 million year over year, and its gaming segment, which includes graphics processors for PCs as well as chips for consoles, reported $1.76 billion in sales, down slightly from $1.88 billion last year. AMD's report comes amid a PC industry slump, with shipments down 30 percent in the first quarter. CEO Lisa Su believes the first quarter was the bottom for the company's client processor business.