The worldwide PC microprocessor market fell into decline last quarter, with market revenue declining 22% year-on-year to $6.78 billion, IDC said.
"The decline in PC processor unit shipments in the fourth quarter was the worst sequential decline since IDC started tracking processor shipments in 1996," said Shane Rau, IDC's director of PC semiconductor research. "The market fell off a cliff in October and November."
Shipments declined 11.4% year-on-year, despite the success of Intel's Atom processor. Without the Atom, unit shipments would have declined 21.6%.
Intel continued to dominate the market, gaining 1.1% market share to 81.9% in Q4. AMD, by contrast, lost 0.9%, and now holds a 17.7% share.
PC processor shipments grew just 10% in 2008, and revenue grew by less than 1% to $30.8 billion. IDC predicts the market will continue to decline in the next two quarters, as demand continues to remain very weak.