For the full year of 2011, IBM had 30.5 percent revenue share, 1.5 percent ahead of its nearest rival, HP, according to Gartner.
The Gartner report also found that IBM was No. 1 in the market for Unix servers, with 52.8 percent market share in the fourth quarter. IBM increased quarterly revenue by 17 percent year-over-year with IBM Power Systems and improved its share 10.9 percent from the fourth quarter of 2010. For the full year of 2011, IBM led the Unix server market, with 45.9 percent market share, a gain of 6.9 points over 2010. IBM grew Unix revenue by 23 percent over 2010, according to Gartner.
IBM led the market for servers costing more than $250,000, attaining 69.4 percent factory revenue share in the fourth quarter with IBM System z mainframes and Power Systems. IBM also led this market for the full year of 2011, with 8 percent revenue growth over 2010, capturing 63.7 percent market share, according to the Gartner report.
Overall, the worldwide server market ended 2011 with mixed results, as worldwide server revenue declined 5.4 percent in the fourth quarter of 2011 and server shipments increased 4.5 percent, according to Gartner.
For the year, worldwide server revenue grew 7.9 percent, and server shipments increased 7 percent, with IBM taking the revenue crown and HP leading in shipments.
"The shortage of hard-disk drive (HDD) inventory because of the Thailand floods in October 2011 provided supply issues, and many providers could not meet the demand in the last weeks of 2011," said Jeffrey Hewitt, research vice president at Gartner, in a statement. "We expect the negative impact of these drive supply issues to continue into 1Q12."