Hall D Trigger and Data Rates Elliott Wolin Hall D Electronics Review Jefferson Lab 23-Jul-2003

Outline 1. Rates from Design Report 2. Comparison with LHC,CLAS… 3. Additional Considerations 4. DAQ Challenges

1. Rates from Design Report High trigger rate – 200 KHz High trigger rate – 200 KHz Deadtimeless, pipelined front ends Deadtimeless, pipelined front ends Small event size – 5 KB Small event size – 5 KB Small Level 1 rejection rate – factor of 2 Small Level 1 rejection rate – factor of 2 Modest rate off detector – 1 GB/sec Modest rate off detector – 1 GB/sec Modest Level 3 rejection – factor of 10 Modest Level 3 rejection – factor of 10 Modest cpu needed in Level 3 – 0.1 SPECint Modest cpu needed in Level 3 – 0.1 SPECint High rate to tape – 100 MB/sec High rate to tape – 100 MB/sec

1. Rates, con’t

2. Comparison with LHC, CLAS… Compared to LHC, Hall D has: Compared to LHC, Hall D has: Similar (LHCb, BTev) or higher trigger rate Similar (LHCb, BTev) or higher trigger rate Much smaller events Much smaller events Much smaller rate off detector Much smaller rate off detector Much smaller total trigger rejection Much smaller total trigger rejection Similar rate to tape Similar rate to tape Less cpu/evt needed in Level 3 Less cpu/evt needed in Level 3

2. Comparison with LHC, CLAS… Compared to CLAS, Hall D has: Compared to CLAS, Hall D has: Much higher trigger rate Much higher trigger rate 200 KHz vs 3 KHz 200 KHz vs 3 KHz Same size events Same size events Approximately the same number channels Approximately the same number channels Much higher rate off detector Much higher rate off detector 1 GB/s vs 25 MB/s 1 GB/s vs 25 MB/s Factor 10 Level 3 rejection Factor 10 Level 3 rejection CLAS has no Level 3 CLAS has no Level 3 Factor 4 higher rate to tape Factor 4 higher rate to tape 100 MB/s vs 25 MB/s 100 MB/s vs 25 MB/s

KTeV Hall D KTev CLAS

BTev CMS Atlas Hall D KTev, CDF, DO, BaBar, CLAS

3. Additional Considerations Can not interrupt ROC every event (200 KHz) Can not interrupt ROC every event (200 KHz) Event blocking in front end cpu’s Event blocking in front end cpu’s Timing and trigger distribution Timing and trigger distribution Note that CLAS has: Note that CLAS has: 25 crates 25 crates 1 Trigger supervisor 1 Trigger supervisor 1 Event Builder and 1 Event Recorder 1 Event Builder and 1 Event Recorder No Level 3 farm No Level 3 farm

Hall D DAQ Baseline Architecture front-end crates Gigabit switch 200 KHz 200 Level 3 Filter Nodes 8 event builders 4 event recorders 4 tape drives 4 Gigabit switches Network connection to silo 20 KHz

3. Additional Considerations, con’t Crates vs networked front end boards? Crates vs networked front end boards? If crates used, VME vs CPCI vs ? If crates used, VME vs CPCI vs ? (RT)Linux vs VXWorks in front end cpu’s? (RT)Linux vs VXWorks in front end cpu’s? Need low-latency interrupt in front end cpu’s? Need low-latency interrupt in front end cpu’s? Location of electronics, crates? Location of electronics, crates? Grounding design? Grounding design?

4. DAQ Challenges All problems solved somewhere, many in CLAS All problems solved somewhere, many in CLAS But new to JLab/CODA: But new to JLab/CODA: Timing distribution Timing distribution Event blocking Event blocking Many more front end crates Many more front end crates Multiple event builders/recorders Multiple event builders/recorders Large Level 3 farm Large Level 3 farm Multiple, simultaneous DAQ systems (for commissioning) Multiple, simultaneous DAQ systems (for commissioning) Need for fault tolerance Need for fault tolerance Integration with control system Integration with control system How are we going to do it? How are we going to do it? See next talk… See next talk…

Backup slides

3. Comparison, con’t EventSize L1 Input Rate L1 output Rate L2 output Rate L3 output Rate KTev 8 KB 100 KHz 800 MB/s 20 KHz 160 MB/s 2 KHz 7 MB/s CDF 270 KB 50 KHz 13 GB/s 300Hz 80 MB/s 80 Hz 23 MB/s D0 250 KB 10 KHz 2.5 GB/s 1 KHz 250 MB/s 70 Hz 13 MB/s BaBar 33 KB (1200 L1) 2 KHz 2.4 GB/s None (65 MB/s) 100 Hz 4 MB/s BTev KB 800 GB/s 80 KHz 8 GB/s 4 KHz 200 MB/s

3. Comparison, con’t EventSize L1 Input Rate L1 output Rate L2 output Rate L3 output Rate Atlas 1-2 MB 75 KHz 100 GB/s 3 KHz 5 GB/s 200 Hz 300 MB/s CMS 1 MB 100 KHz 100 GB/s 100 Hz 100 MB/s CLAS 6 KB 4 KHz 4KHz 25 MB/s 4KHz Hall D 5 KB 400 KHz 200 KHz 1 GB/s none 20 KHz 100 MB/s