The research firm predicts "a soft landing" for the server market in the second half, Scaramella said.

Still, for now business was brisk in all segments. Sales of volume systems, which by IDC's definition cost less than $25,000, were up 17 percent from a year earlier, while sales of midrange systems, priced from $25,000 to $250,000, were up by the same amount. Sales of high-end systems -- those priced above $250,000 -- climbed 23 percent, IDC said.

The high-end sales undoubtedly were helped by IBM's System z mainframe sales, which were up 61 percent from a year earlier, to $1.2 billion. Blades also performed well, with revenue up 27 percent year over year, IDC said.

All vendors saw their server revenue increase from a year earlier. Fujitsu, the smallest of the top five vendors, saw its revenue more than double, largely thanks to the K-computer high-performance computing system in Japan. It finished the quarter with 6.5 percent market share, in a statistical tie with Oracle, whose sales increased just 4.2 percent.

Dell's server sales increased by 5.1 percent, IDC said, putting it in the middle of the pack with revenue of $1.8 billion.