AMD reported fourth-quarter earnings of $0.77 per share on revenue of $6.17 billion, beating estimates on the top and bottom lines. AMD's guided revenue for the first quarter of $5.4 billion, below the analyst estimate of $5.73 billion. AMD cited flat sequential growth expected in its key data center segment, with a graphics processor ramp offsetting a server sales decline. AMD stock dropped more than 6% in after-hours trading on Tuesday.