The Europe, Middle East and Africa regions were a source of very strong growth in the quarter -- rising more than 20 percent -- and other regions also turned in a respectable performance, IDC said.
Despite concerns of rising interest rates, oil prices and efforts to manage the Chinese economy, business investment and rising consumer interest in cheaper PCs are driving market growth in the Asia Pacific region, IDC said.
Year over year growth in the United States bounced back from a first quarter that was hampered by slow public sector spending and a difficult comparison to a year ago, IDC said. Consumer demand and the public sector also improved.
Overall, worldwide shipments of PCs rose to 46.6 million, up 16.6 percent from 39.9 million PCs in the year-ago second quarter, IDC said. IDC's May forecast called for worldwide PC growth of 12.3 percent.
Charles Smulders, a Gartner analyst, said that demand for notebook PCs helped drive sales, and price cuts on desktop PCs also drove higher unit shipments.
Consumer demand in Japan continues its recovery, IDC said, noting that growth is now rising in response to lower prices and aging PCs that need to be replaced.
In terms of the top PC makers, Dell Inc. , the largest PC vendor, had yet another strong quarter, with global unit shipments increasing nearly 24 percent to 8.98 million, giving it a worldwide PC market share of 19.3 percent, up from 18.2 percent a year ago.
Hewlett-Packard Co. retained its No. 2 spot, with unit growth of 16 percent, to 7.25 million PCs shipped in the second quarter. HP's market share in the second quarter was 15.6 percent, IDC said.
Lenovo Group Ltd. , the No. 3 PC maker, appeared to be "working through its merger issues fairly well," IDC said. The company bought IBM's PC business. Lenovo, including the IBM PC business, ended the quarter with 7.6 percent of the worldwide PC market, up from 2.4 percent a year earlier.
Gateway Inc. , which a year ago bought its smaller, profitable rival eMachines, also gained share, rising to 6.0 percent of the U.S. market in the second quarter, from 5.3 percent a year ago.
Apple Computer Inc. , too, increased its share of the U.S. PC market during the second quarter, rising to 4.5 percent from 3.7 percent a year ago, as global unit shipments rose more than 37 percent, IDC said.
IDC said that the Mac mini as well as its digital music business and the iPod digital music player have "clearly benefited the company's PC business."