The GRID Computing Face with the Start of the LHC Experiments

The biggest particle accelerator in the world, the LHC, began to work in August 2008 and the four high energy experiments (ALICE, ATLAS, CMS and LHCb) hosted in the beam crossing caverns start to take data. The amount of collected data was very huge ( about several PB) and the grid infrastructure developed and deployed in the last 9 years was monitored and put under challenging situations. In this talk a review of the main parts of the LCG, the LHC computing grid project, was explained and the recent performance studies obtained at CERN was presented. A special description of the ATLAS computing model was given.