A quarterly report from industry analyst IDC indicates that PC shipments have been unusually soft. According to the group, PC sales dipped 6.4 percent in Q4 2012 when compared to the same period last year. Additionally, Q4 led to a 4.5 percent decline in sales from the previous quarter and marked a 7 percent drop for 2012, overall.

An independent report by research firm NPD corroborates IDC's findings of a decline during the same period, but raises that figure to a whopping 11 percent when looking at just U.S. sales. Many analysts expected Windows 8 and week-long holiday sales to invigorate Q4 PC sales; however, relatively poor retail performance may instead be a troubling sign for PC makers.

Although numbers in 2012 were smaller than 2011, manufacturers still managed to squeeze out 352.4 million PCs – shrinking or not, PCs remains an enormous industry. According to IDC, HP remained the largest global PC vendor in Q4 with 16.7 percent market share. Lenovo and Dell rounded out the top three with 15.7 and 10.6 percent, respectively. When it comes to sales within the United States, HP, Dell and Apple held the top spots with 27.0, 19.6 and 11.4 percent of market share, respectively.

Notably, unlike Canalys and a small minority of research firms, IDC does not consider tablets as PCs or "personal computers". However, IDC does count Apple computers, laptops and netbooks as PCs. Also excluded from the results are servers and handhelds.

IDC supposes the drop in PC sales is driven primarily by strong demand for tablets and smartphones. There has long been a debate over whether tablets could cannibalize PCs, but as PC sales slow, tablets have only gained momentum.