Talking about ATLAS experiment: protons in LHC collide 40 million times a second, but "only" around 100 events per second are stored for later analysis. LHC gri

Talking about ATLAS experiment: protons in LHC collide 40 million times a second, but "only" around 100 events per second are stored for later analysis. LHC grid concerns the 100; three levels of trigger (one hardware and two software levels) are used to select the useful 100 out of 40 millions, in real time.