Worldwide server sales were up 4 percent during the first quarter of 2005, according to research from Gartner.

Total server revenue for the quarter was US$12.33 billion, up from $11.84 billion during the first quarter of 2004. IBM, Hewlett-Packard and Dell were the top three server vendors, with sales of $3.67 billion, $3.47 billion and $1.33 billion for the period.

With a 16 percent rise in sales of "x86" servers, which use processors from Intel and AMD, HP actually shipped the largest number of servers by a wide margin. HP shipped a total of 498,000 servers during the quarter, followed by Dell and IBM, which sold 402,000 and 183,000 systems, respectively.

Sales of servers with AMD's Opteron processor accounted for 5.7 percent of the 1.6 million unit x86 market. This was a slight improvement from the 5.4 percent market share Opteron held during the previous quarter, but still far from AMD's stated goal of 12 percent market share by year's end.

In total, 92,000 Opteron systems shipped during the quarter, led by HP, with just under 12,000 shipments, and Sun, which sold nearly 9,000 Opteron servers. The vast majority of Opteron sales, however, were made by smaller, lesser-known vendors.

Intel's 64-bit Xeon processor accounted for 797,000 systems sold during the quarter.

"Opteron is still a viable product," said Joseph Gonzalez, a Gartner analyst. "You can run a lot of your older applications on it. It's also a little bit lower-priced than some of the Xeon offerings," he said. "It's not going to make a huge inroad into Intel's sales, but it's going to bring in a lot of revenue for AMD."

Unix sales were up slightly for the quarter, but IBM was the only one of the top three vendors to see its Unix business grow. Big Blue had Unix sales of $1.23 billion for the quarter, followed by HP, which had sales of $1.17 billion. Third-place Sun Microsystems saw its Unix sales drop from $1.21 billion to $1.13 billion, year over year.

Despite marketing efforts to promote itself as an x86 vendor, Sun's overall revenues dropped as well during the period. During the first quarter of 2004 Gartner estimates it sold $1.22 billion in servers. For the most recent quarter, sales dropped to $1.17 billion.