Apple's iPads account for one out of every six PCs sold in the market today, according to research firm Canalys.
The company said that over the fourth quarter, Apple's tablet led the way in sales and, when combined with its Macintosh line, made the company the top vendor in the PC market ahead of HP.
Canalys reported that in the quarter Apple gained a 20 percent share of the market, while HP weighed in at an 11.7 percent share.
Tablets in general sold well, with shipments up 75 percent over the previous quarter. Canalys estimated that one third of all PCs sold in the quarter were in tablets. The PC market as a whole was up 12 percent over the previous year's quarter.
When tablets are separated from the traditional PC form factors, however, the sales picture becomes much more grim. Canalys reported that notebook sales were flat year-on-year, while traditional PC heavyweights Dell and HP saw their shares of the market drop.
The figures are the latest in an ongoing decline for the notebook and desktop PC market at the hands of tablets. A number of firms reported that PC market growth has slowed or declined in 2012, while the tablet space continues to put up record sales numbers.
Not all vendors are reaping the benefits of the booming tablet market, however. Researchers noted that the Windows RT platform moved just 720,000 units, a three percent share of the total market.
"The outlook for Windows RT appears bleak. Hardware OEMs are ignoring it due, in part, to a pricing strategy that does not align with the economics of the pad market," explained Canalys senior analyst Tim Coulling.
"We expect Microsoft to rethink its pricing strategy for RT in the coming weeks. Dropping the price by 60 percent should get OEMs back onside."