The market research firm said it is most severe fall since records began.
Shipments in 2014 are also set for fall by a further 3.8 percent with total PC shipments staying at 300 million.
Interest in PCs has waned, but IDC said that enterprise sales are performing far better although still falling by five percent year on year. But, said Jay Chou, a senior analyst at the company, the long term outlook for commercial and consumer markets is not significantly different.
Even developing markets are showing a fall.
He said: “Perhaps the chief concern for future PC demand is a lack of reasons to replace an older system. While IDC research finds that the PC still remains the primary computing device – for example, PCs are used more hours per day than tablets or phones – PC usage is nonetheless declining each year as more devices become available. And despite industry efforts, PC usage has not moved significantly beyond consumption and productivity tasks to differentiate PCs from other devices. As a result, PC lifespans continue to increase, thereby limiting market growth.”
And so to PC tablets running Windows. While in 2017 it is expected to grow to 39.3 million units, from the 2013 figure of 7.5 million, such tablets will only add a few percentage points a year to PC growth.