IBM is no longer king.
The lead position on ORNL's Top 500 Supercomputer list is now Cray's XT5 "Jaguar" supercomputer, besting IBM's Roadrunner.
The XT5 Jaguar, located at Oak Ridge National Lab in Tennessee, recently received a refresh that included upgrading its quad-core CPUs to hex-core Opteron processors. That means a 2.3 petaflop per second theoretical performance peak ("nearly a quarter of a million cores"), and 1.75 petaflops measured by the Linpack benchmark.
In comparison, IBM's Roadrunner managed 1.042 petaflops. (One petaflop per second is equivalent to one quadrillion calculations per second.)
Irrelevant factoid that may only interest me: Four of the top five systems are based on AMD tech, while 402 of the top 500 are powered by Intel.
Care to see what upgrading a supercomputer looks like? The video, below:
Last fact: The U.S. remains the leading consumer of supercomputers with 277 of the top 500 systems. Europe has 153 systems (UK 45, France 27, Germany 27) and Asia owns 50 systems (China 21, Japan 16, India 3).