IBM has maintained its market leading position in the server market thanks to growing demand for high end systems, according to IDC.

The analyst said IBM had been buoyed by a favourable product refresh cycle which had seen overall spending on high end systems increase 6.4% in the fourth quarter of 2012. This boost in demand helped IBM, which controls 36.5% of the server market, deliver its highest quarterly revenues for System z mainframes in more than a decade.

IDC claimed volume systems had also experienced a 4.2% growth in revenues due to increased investments in efficiency technologies such as virtualisation. “Large and small enterprises continued to invest heavily in new server capacity to drive additional consolidation and virtualisation initiatives,” said Matt Eastwood, general manager of enterprise platforms at IDC.

Overall worldwide server shipments have, however, decreased 3.9% – although there are some specific areas of year on year growth. Blade servers, which are highly leveraged in enterprises’ virtualised environments, grew 3.3%. Blades now account for 16.3% of total server revenue.

Density optimised servers, utilised by large data centres, also saw shipments increase 44.2%. “Both types of modular form factors outperformed the overall server market, indicating customers are increasingly favouring specialisation in their server designs,” said Jed Scaramella, research manager at IDC.