Intel admitted the impact of weak spending on servers to the company's fourth quarter earnings, but CEO Brian Krzanich remained optimistic about 2014. Intel said on Thursday it overestimated the extent of a recovery in spending among its enterprise customers. In the December quarter, Intel's PC revenue stayed flat, which it said was slightly better than the company expected.

Personal computer sales are losing ground to tablets and smartphones. Intel plans to double its mobile efforts. The company unveiled its latest connected technologies at the Consumer Electronics Show earlier this month. Krzanich pointed towards tablets, adding that Intel hopes to grow tablet volume to 40 million units this year. The chip maker finished off 2013 with more than 10 million units. He also noted that Intel plans to have approximately 70 more new, unique 2-in-1 designs ready by back-to-school season.

The company has also bet that sales of high-end server chips will help offset lower revenue from PCs this year. But Intel's executives said Intel's data center group revenues in 2014 would probably come in toward the bottom of their previous growth estimate of 10 percent to 15 percent.

Intel posted fourth-quarter net earnings of $2.6 billion, compared with $2.5 billion in the year-ago quarter. Revenue for the same period was $13.8 billion, compared with $12.5 billion in the year-ago quarter. The reported 8 percent increase in server revenue in the fourth quarter was less than Intel expected.

Intel forecast revenue of $12.8 billion, plus or minus $500 million, for the first quarter, which ends in March.