Rackspace is one of the fastest-growing cloud computing providers. The San Antonio company spent $202 million on servers and storage for customers over the past year, adding more than 12,000 servers in its data centers.

via How Open Compute is a Win for Rackspace » Data Center Knowledge.

To put this in perspective, Amazon EC2 has over 450,000 servers according to this article.

At the Open Compute Summit earlier this month in San Antonio, both Dell and HP showed off server hardware that will work with the new Open Rack design, which features 21-inch wide equipment slots rather than the traditional 19 inches. Roenigk says Open Rack will play a key role in Rackspace’s cloud computing infrastructure in its next-generation data center design.