4 ms·
"generate up to 10 gigabytes of data" That's got to be misprint .
by tosseraccount 11y ago
"generate up to 10 gigabytes of data"
That's got to be misprint .
- IceyEC 11y agoin one second.
- tosseraccount 11y agoHow long do the collisions last? Is this sustained over seconds?
- lutorm 11y agoIIRC, the beams intersect a few times in the 26km diameter tunnel, where the bunches go around at the speed of light. Depending on how many bunches there are, that's ~ thousands of beam intersections per second. How many particle collisions there are per intersection depends on how densely packed the particles are and how many of them there are, known as the "luminosity" of the beam. And yes, in a "run", this is sustained indefinitely.
- daveloyall 11y agohttps://en.wikipedia.org/wiki/Worldwide_LHC_Computing_Grid https://en.wikipedia.org/wiki/Worldwide_LHC_Computing_Grid
- tosseraccount 11y agothanks. "The data stream from the detectors provides approximately 300 GByte/s of data, which after filtering for "interesting events", results in a data stream of about 300 MByte/s. The CERN computer center, considered "Tier 0" of the LHC Computing Grid, has a dedicated 10 Gbit/s connection to the counting room."
- batbomb 11y agoNot all data is detector data. This is usually what we'd call Level 0 or Level 1 data. The lower levels aren't usually that interesting for analysis, because they might not be properly calibrated or even reconstructed, depending on the detector. Reconstruction takes an immense amount of CPU time so it's not practical to do on the fly, so you have to store reconstructed data, and that takes up space. Then you might store (re)calibrated data and have several generations of that. Then you reprocess all of your data as a new pass, then you have several passes of data, constructed with different calibrations and algorithms. Not mentioned is simulation (monte carlo) datasets. Their size is usually within an order of magnitude of your actual data size. For some experiments, the amount of simulation data may eclipse the amount of actual data they have. I can't comment on the size and composition of ATLAS/CMS data, but my guess is the rate at which data is generated for the experiments, using a broader definition, is easily within an order of magnitude to that of Youtube.
- epistasis 11y agoI'm not sure if you think it's a misprint because it's too small, or two big.
- GFK_of_xmaspast 11y agoAs i interpret it, the article says there are up to 1B collisions per second, and at only ten bytes per collision you get 10gb/s right away.
- welterde 11y agoLooking at the data rates of just the ATLAS detector [1] the data rate of about 10 GB/s for all experiments sounds about right (with higher event rates in the current run and detector upgrades). And that's after throwing away 99.99% of all events! The raw data rate is >64 TB/s (with about 1.6 MB per event)! [1] http://www.atlas.ch/pdf/atlas_factsheet_4.pdf http://www.atlas.ch/pdf/atlas_factsheet_4.pdf