Hewlett-Packard (NYSE: HPQ) in the first quarter toppled IBM (NYSE: IBM) from the top of the server market based on revenue, besting Big Blue by less than 1%, market research firm Gartner said Thursday.

Total worldwide server shipments rose by 7.6% over the same quarter a year ago to 2.3 million units, and revenue climbed 4.3% to $13.6 billion, Gartner said. Shipments and revenue from x86 servers increased. RISC-Itanium Unix servers fell in shipments, but grew slightly in revenue...