You'd think that with a price tag of billions of dollars the LHC would have more storage capacity than it could ever use. But with the machine producing a petabyte of data every second, the researchers simply can't store it all.
To put that into perspective, a petabyte is a million gigabytes, or enough capacity to store 13.3 years of HDTV content. And that's how much data the LHC's sensors are producing every second during an experiment. That's insane, and understandably, the facility simply doesn't have the capacity to save all that data.
When a collision occurs, the LHC's detectors capture somewhere in the neighbourhood of 40 million snapshots in a single second. And that petabyte of data is then processed by a sophisticated array of electronics that decides what snapshots might actually have useful data in them, paring it down to about 100,000. That smaller group is then sent to a large farm of in-house computers which further narrows down the results to anywhere from 100 to 300 snapshots, which can then be sent to a network of computers around the world for detailed analysis. And you complain because your DVR had to delete an episode of Mad Men to make room for the latest episode of Game of Thrones. Tsk tsk. [YouTube]