Mac sales may have risen by almost 30 per cent year over year in the final quarter of 2013, according to new estimates from research firm Gartner. That's despite the struggles that the PC market as a whole is facing due to competition from tablet devices.

Gartner's predictions suggest that Apple's US PC marketshare has risen from 9.9 per cent to 13.7 per cent over the Christmas quarter compared with the same quarter in 2012, perhaps thanks to 2013's updates to the iMac, Retina MacBook Pro and MacBook Air. That increase appears to have come at the expense of HP and Toshiba, which Gartner expects have seen a decrease in PC shipments of 10 to 14 per cent each.

Overall, the PC market is believed to have declined by 7.5 per cent, with a total of 15.8 million units shipped in the US during the fourth quarter of 2013, down from 17.07 million units the previous year.

"Holiday sales of technology products were strong in the US market, but consumer spending during the holidays did not come back to PCs and tablets were one of the hottest holiday items," said Gartner's principal analyst Mikako Kitagawa. "We think that the US PC market has bottomed out. A variety of new form factors, such as hybrid notebooks, drew holiday shoppers' attention, but the market size was very small at the time."

It's worth noting that these predictions are preliminary estimates, and may not eventually reflect the actual figures. We'll find out Apple's official figures for the last quarter on 27 January. However, should the estimates prove to be accurate, 2013 may have been the seventh consecutive year for Apple's PC marketshare growth.