Cisco has entered the list of the top five server vendors for the first time, drawing level with Fujitsu and Oracle in a tie for fourth place, research firm IDC said yesterday.

It's a symbolic victory for Cisco that comes four years after the networking vendor entered the server market with its Unified Computing System, combining compute, network and virtualisation resources in a single box.

Its share of the market still lags far behind that of IBM, HP and Dell, but IDC's results are a further sign that Cisco is a serious player in the server business.

Cisco ended the fourth quarter with 3.3% of server systems revenue, compared with 3.4% for Fujitsu and 4.1% for Oracle. That put the three vendors in a statistical tie for fourth place, IDC said. Oracle's server business fared worst, declining 18% from the fourth quarter of 2011, while Cisco's surged 51%.

At the top of the market, IBM retained its lead with 36.5% of server sales, followed by HP with 24.8% and Dell with 15.1%, IDC said.

The fourth quarter was a good one overall for the server industry, at least compared to the rest of the year. Sales were up 3.1% from the final quarter of 2011, to $14.6 billion. That marked the first quarterly increase in server revenue in five quarters, IDC said.

The full-year picture wasn't so good, with overall sales down 1.9% from 2011, at $51.3 billion.

The quarterly sales increase was driven by x86 servers, with revenue up 4.2%, and high-end systems, which were up 6.4%, thanks largely to the release of a new IBM mainframe last August.

"The IBM System z mainframe platform had its highest quarterly revenue since 1997, generating nearly $2 billion and driving the overall server market to positive growth in the quarter," IDC analyst Jean Bozman said.

Revenue from midsized systems, including many types of Unix servers, declined 10%, IDC said.

Quarterly server sales were up sharply in the US, Asia/Pacific and Latin America, but weak everywhere else, IDC said.

Gartner also released its server market-share figures yesterday. Cisco made Gartner's top five for the volume of servers it sold, something it has achieved before, but not for server revenue.