Application of PC's and Linux to the CDF Run II level-3 trigger
J. Fromm, D. J. Holmgren, R.D. Kennedy, Jim Patrick, D. Petravick, R. Rechenmacher, G. P. Yeh, G. Bauer, P. Sphicas, S. Tether, Jeff Tseng, B. Kilminster, Kevin S. McFarland, Kirsten Tollefson · University of North Texas Digital Library (University of North Texas) · 1998
For Run II, the CDF Level-3 trigger must provide a sustained input bandwidth of at least 45 MBytes/set and will require processing power of at least 45000 MIPS to perform the necessary reconstruction and filtering of events. We present a distributed, scalable architecture using commod- ity hardware running the Linux operating system. I/O and CPU intensive functions are separated into two types of nodes; converter nodes receive event fragments via ATM from Level 2 computers and distribute complete events to processor nodes via multiple fast ethernets. We present re- sults from a small-scale prototype roughly equivalent to a 1/16th vertical slice of the final system. With this hardware we have demonstrated the capability of sustained I/O rates of 15 MBytes/set, more then three times the required baseline performance. We discuss PC hardware and Linux software issues and modifications for real time performance.