Helped by a surge in mainframe sales, IBM's revenue climbed to just over US$4 billion in the quarter, giving it 30.5 percent of the overall market. HP's sales climbed a more modest 9.3 percent, to $3.9 billion, for 29.8 percent of the market. IBM crowed that it had recaptured the server crown, but IDC declared it "a statistical tie."

Server sales were strong overall, with worldwide revenue climbing 18 percent from a year earlier to $13.2 billion, IDC said. Unit shipments were 2.1 million, the second-highest total ever reported for a June quarter. The highest was in 2008, just before the economy went south.

"These numbers were actually slightly better than we were expecting," said IDC analyst Jed Scaramella.

Recent Unix upgrades from HP, IBM and Oracle helped lift the results, as did new mainframes from IBM. In addition, companies that put off buying new gear during the recession finally had to make purchases, IDC said.

The second half of the year won't be so rosy, however. The refresh cycles are starting to dry up and "weakening macroeconomic concerns around the world will serve to moderate demand for servers later this year," IDC said in a statement.