Performance of the L3 second level trigger implemented for the LEP II with the SGS Thomson C104 packet switch
- LAPP/IN2P3, Annecy-le-Vieux (France)
- MIT, Cambridge, MA (United States). L.N.S.; and others
The L3 experiment is one of the four experiments collecting data at LEP. For the LEP phase 2, the second level trigger has been upgraded to a network of 28 ST T9000 transputers and 2 ST C104 asynchronous packet switches interconnected by IEEE1355 links. It collects trigger data at each LEP crossing (22 {micro}s), builds-up the trigger data block, processes it and rejects online the background events in a few milliseconds. The L3 data acquisition has been running with this system since July 1995. In the data-taking environment and for different hardware and software implementations, the event building throughput rate has been measured. A bandwidth of 5.9 Mbytes per second per link has been measured in a configuration with 12 sources and one processing unit connected with 2 links. The expected global throughput of 70 Mbytes per second has been measured in a farm of 6 processing units. While varying the number of sources and destinations, the authors didn`t observe any significant bandwidth loss. Nevertheless performance relies strongly on some software implementation choices, which are presented and discussed.
- OSTI ID:
- 665237
- Report Number(s):
- CONF-9709140-; ISSN 0018-9499; TRN: 98:011713
- Journal Information:
- IEEE Transactions on Nuclear Science, Vol. 45, Issue 4Pt1; Conference: 10. IEEE real time conference, Beaune (France), 22-26 Sep 1997; Other Information: PBD: Aug 1998
- Country of Publication:
- United States
- Language:
- English
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