Inside Cern's atom-smasher number-cruncher

The grid institutions use middleware created by Cern scientists to process LHC data. This diagram shows Cern as the initial, 'Tier 0' processing centre. The data that Cern has no capacity to process is farmed out to 11 'Tier 1' centres for storage, from where the data is processed by the remaining 'Tier 2' institutions. "The users are physicists located in the Tier 2 centres," Jouanigot said.