Following the estimate by IDC that PC sales will barely grow in 2011, rival research company Gartner has followed suit, trimming its forecast from 10.5% growth in sales to 9.3%.
It says that it now expects 385m units to be sold worldwide, as consumers show less interest in PCs (and especially less in netbooks) and businesses become the prime engine of sales as they replace machines still running Windows XP.
The forecast compares to just under 350m PCs sold worldwide in 2010, by Gartner's figures. IDC says that 346.5m were sold that year - but its forecast for 2011, of 361.6m, is noticeably lower than Gartner's 385m.
However, the difference of 3.25% is exactly the same as the long-term difference between the companies' quarterly figures going back to 1998, suggesting that their slightly different ways of measuring shipments are the cause.
IDC cut its forecast more substantially in percentage terms, halving it for this year while forecasting more rapid growth next year.
Gartner's research director Ranjit Atwal said: "Consumer mobile PCs are no longer driving growth, because of sharply declining consumer interest in mini-notebooks. Mini-notebook shipments have noticeably contracted over the last several quarters, and this has substantially reduced overall mobile PC unit growth."
He added: "Media tablets, such as the iPad, have also impacted mobile growth, but more because they have caused consumers to delay new mobile PC purchases rather than directly replacing aging mobile PCs with media tablets. We believe direct substitution of media tablets for mobile PCs will be minimal."
But he also sees a transition underway from a "one size fits all" computing to more specialised devices which are able to complement other devices. "The PC market is experiencing dramatic structural changes," said Atwal. "PCs will no longer be a market by themselves, but part of a larger device market that ranges from smart televisions to the most-basic-feature phones."
He expects businesses to drive growth in the next 18 months, even while consumers sit the market out or buy other products. "Businesses sharply reduced replacements and extended PC lifetimes in response to the recession," said Raphael Vasquez, research analyst at Gartner. "Businesses have begun replacing aging PCs more vigorously. We expect the growing urgency for businesses to migrate away from Windows XP will drive significant professional replacements."
George Shiffler, another Gartner research analyst, said PC vendors had only experienced minor disruptions to shipment growths from the Japanese earthquake and tsunami in March, though forecast PC shipment growth in the country itself was cut to just 2.4% for the year.
