As part of its post-2008 business overhaul, Citigroup has consolidated its formerly massive data center infrastructure, going from 70 facilities to 20 in about five years, Wall Street and Tech reported.

The publication quoted the financial-services giant’s head of enterprise operations and technology Jagdish Rao, saying, “We are near to the end of a five year data center consolidation strategy. This is a massive consolidation that follows our global operational model.”

Rao’s team shut down older data centers and some data centers inherited with acquisitions and built eight new critical facilities around the world, including its LEED (Leadership in Energy and Environmental Design) Platinum data center in Frankfurt, famous in the industry for being the first data center LEED-certified at the Platinum level ever.

All new data centers have LEED certification of some sort, Rao told Wall Street and Tech.

As a result of the consolidation project, the cost of doing business has gone down “drastically”, he said.

Before the consolidation, the company spent 60% of its IT budget on infrastructure and management, the rest funding application development. These percentages have been reversed, Rao said.

Much of the consolidation was achieved through massive server virtualization. Citi virtualized 40,000 physical servers – an infrastructure that now runs at 40-50% of its capacity.

The utilization rate is a major improvement from 5-10% utilization rate Rao said the company had prior to the overhaul.

Citi has also set up its IT infrastructure as private cloud, which improved not only its server utilization rate, but also the utilization rate of storage. About 72 petabytes of data is stored in the company’s data centers.