The Cray Jaguar is officially the most powerful computer in the world, dethroning the IBM Roadrunner. IBM had spent five years at the top of the list, with the Jaguar, a Cray XT5 model, coming in at number 3. The performance boost was achieved by changing out the quad core Opterons in the computer for the new six core Istanbul processors. The new total of 224,000 processing cores gives the Jaguar a peak performance of 1.75 petaflops. The Jaguar is located at the Oak Ridge National Lab, where it is used for a variety of science and engineering applications.