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CBM at FAIR. New challenges for Front-End Electronics, Data Acquisition and Trigger Systems. Walter F.J. Müller , GSI, Darmstadt XXXVI. Treffen "Kernphysik" , Schleching/Obb., 17-24 February 2005 Vortrag zum Thema: Hochleistungsdatenverarbeitung in der Kern- und Teilchenphysik. Outline.
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CBM at FAIR New challenges for Front-End Electronics, Data Acquisition and Trigger Systems Walter F.J. Müller, GSI, Darmstadt XXXVI. Treffen "Kernphysik", Schleching/Obb., 17-24 February 2005 Vortrag zum Thema: Hochleistungsdatenverarbeitung in der Kern- und Teilchenphysik
Outline • CBM (very briefly) • observables • setup • FEE/DAQ/Trigger • requirements • challenges • strategies XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM at FAIR SIS 100 Tm SIS 300 Tm U: 35 AGeV p: 90 GeV Compressed Baryonic MatterExperiment XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Mapping the QCD Phase Diagram • RICH/LHC: • explore μB → 0 • travel back to the early universe • CBM • explore μB → max • travel into a neutron star • 10 – 45 AGeV • 2nd generation experiment • penetrating probes • rare probes XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM Physics Topics and Observables • In-medium modifications of hadrons onset of chiral symmetry restoration at high ρBmeasure: , , e+e- (μ+ μ-) open charm: D0, D± • Strangeness in matter enhanced strangeness productionmeasure: K, , , , • Indications for deconfinement at high ρB anomalous charmonium suppression ?measure: D0, D± J/ e+e- (μ+ μ-) • Critical point event-by-event fluctuations measure: π, K Good e/π separation Vertex detector Low cross sections→ High interaction rates→ Selective Triggers Hadron identification XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM Setup Radiation hard Silicon pixel/strip detectorsin a magnetic dipole field Electron detectors: RICH & TRD & ECAL: pion suppression up to 105 Hadron identification: RPC, RICH Measurement of photons, π0, η, and muons: ECAL XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM and HADES All you want to know about CBM:Technical Status Report (400 p)now publicly available XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Meson Production in central Au+Au W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745 10 MHz interaction rateneeded for 10-15 A GeV SIS300 XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Open Charm Detection • Example: D0 K-+ (3.9%; c = 124.4 m) • reconstruct tracks • find primary vertex • find displaced tracks • find secondary vertex target few 100 μm 5 cm • high selectivity because combinatorics is reduced first two planesof vertex detector XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
A Typical Au+Au Collision Central Au+Au collision at 25 AGeV: URQMD + GEANT 160 p 170 n 360 -330 +360 0 41 K+ 13 K-42 K0 107 Au+Au interactions/sec 109 tracks/sec to reconstruct for first level event selection XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM Trigger Requirements assume archive rate: few GB/sec 20 kevents/sec • In-medium modifications of hadrons onset of chiral symmetry restoration at high ρBmeasure: , , e+e- open charm (D0, D±) • Strangeness in matter enhanced strangeness productionmeasure: K, , , , • Indications for deconfinement at high ρB anomalous charmonium suppression ?measure: D0, D±- J/ e+e • Critical point event-by-event fluctuations measure: π, K offline trigger trigger ondisplaced vertex offline drives FEE/DAQarchitecture trigger trigger trigger on high pte+ - e- pair offline XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM DAQ Requirements Profile • D and J/Ψ signal drives the rate capability requirements • D signal drives FEE and DAQ/Trigger requirements • Problem similar to B detection, like in BTeV, LHCb • Adopted approach: displaced vertex 'trigger' in first level, like in BTeV • Additional Problem: DC beam → interactions at random times → time stamps with ns precision needed → explicit event association needed • Current design for FEE and DAQ/Trigger: • Self-triggered FEE • Data-push architecture XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Buffer Conventional FEE-DAQ-Trigger Layout Especially instrumented detectors Detector L0 Trigger fbunch Trigger Primitives Dedicated connections FEE Cave Limited capacity Shack L1 Accept DAQ Modest bandwidth L2 Trigger L1 Trigger Limited L1 trigger latency Specialized trigger hardware Standard hardware Archive XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Limits of Conventional Architecture Decision time for first level trigger limited. typ. max. latency 4 μs for LHC Not suitable for complex global triggers like secondary vertex search Only especially instrumented detectors can contribute to first level trigger Limits future trigger development Large variety of very specific trigger hardware High development cost XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Buffer L2 Trigger L1 Trigger L2 Trigger The way out .. use Data Push Architecture Especially instrumented detectors Detector L0 Trigger fbunch fclock Trigger Primitives Dedicated connections FEE Timedistribution Cave Limited capacity Shack L1 Accept DAQ High bandwidth Modest bandwidth L1 Trigger Limited L1 trigger latency Specialized trigger hardware Standard hardware Special hardware Archive XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
L1 Trigger L2 Trigger The way out ... use Data Push Architecture Detector fclock FEE Cave Shack DAQ High bandwidth Special hardware Archive XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
L1 Select L2 Select The way out ... use Data Push Architecture Detector Self-triggered front-end Autonomous hit detection fclock FEE No dedicated trigger connectivity All detectors can contribute to L1 Cave Shack DAQ Large buffer depth available System is throughput-limited and not latency-limited High bandwidth Modular design: Few multi-purpose rather many special-purpose modules Special hardware Use term: Event Selection Archive XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM DAQ and Online Event Selection • More than 50% of total data volume relevant for first level event selection • Aim for simplicity • Simple two layer approach: 1. event building 2. event processing neededfor D neededfor J/μ usefullfor J/μ STS, TRD, and ECAL data usedin first level event selection XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Logical Data Flow Concentrators:multiplex channelsto high-speed links Time distribution Buffers Build Network Processing resources forfirst level event selectionstructured in small farms Connection to'high level' selection processing XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Bandwidth Requirements Data flow: ~ 1 TB/sec Gilder helps Moore helps 1st level selection: ~ 1014-15 operation/sec Data flow: few 10 GB/sec to archive: few 1 GB/sec XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
L1 Event Selection Farm Layout • Current working hypothesis: CPU + FPGA hybrid system (proviso follows) • Use programmable logic for cores of algorithms • Use CPU for the non-parallelizable parts • Use serial connection fabric (links and switches) • Modular design (only few board types) XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
FPGA – Basic Building Block CLB = Configurable Logic Block CLB X F0 D Q XQ F1 LUT F2 C F3 CLK Elementarystorage unit Universallogic gate Look-up Tablejust a 4x1 RAM D Flip-Flop XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
FPGA – Putting it together CLB CLB CLB CLB ConfigurableLogic Block PSM PSM PSM Wiring CLB CLB CLB CLB Programmableswitch matrix PSM PSM PSM I/O blocks CLB CLB CLB CLB PSM PSM PSM Modern FPGA's:>100.000 LUT 500 MHz CLB CLB CLB CLB XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Algorithms • Performance of L1 feature extraction algorithms is essential • critical in CBM: STS tracking + vertex reconstruction TRD tracking and Pid • Look for algorithms which allow massive parallel implementation • e.g. Hough Transform Trackerneeds lots of bit level operations, well suited for FPGA • Caveat: simulation on normal CPU quite time consuming.... • Co-develop tracking detectors and analysis algorithms • L1 tracking is necessarily speed optimized→ more detector granularity and redundancy needed • Aim for CBM:Validate final hardware design with at least 2 trackers suitable for L1 XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Interim Summary • Event definition has changed: • now based on time stamps and time correlation • Role of DAQ has changed: • DAQ is simply responsible to transport data from producers to consumers • Role of 'Trigger' has changed: • filter events delivered by DAQ • 'Online Event Selection' is better term • System aspects: • 'online' – 'offline' boundary blurs • more COTS (commercial off the shelf) components • much more modular system • much more adaptable system • This is emerging technology in HEP, though baseline for ILCHowever: being used since many years in nuclear structure XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Moore – quo vadis ? • Will price/performance of computing continue to improve ? • What are limits of CMOS technology ? • Where are the markets ? What are market forces ? • Technology • most of the gain comes from architecture anyway • conventional designs, especially x86, reach their limits • Markets • end of the metal-box PC age→ Laptops + PDA + all kind of dedicated boxes (Video, Games) • end of the binary compatibility age → intermediate code + 'Just in Time' Compilers (JIT) There is life after Intel x86A lot of architectural innovation ahead XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CPU CPU CPU Cache Cache Cache Mem IO Mem IO IO IO IO Mem IO SPE Mem Mem SPE SPE Mem Mem SPE SPE Mem Mem SPE SPE Mem Mem SPE BlueGene vs Cell Processor BlueGene:121 mm2; 130 nm2.8/5.6 DP GFlop STI Cell:221 mm2; 90 nm256 SP GFlop 30 DP GFlop 25 GB/sec mem 78 GB/sec IO Finally presentedon ISSCC 2005 International Solid-State Circuit Conf. SPE = Synergistic Processing Element XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
BlueGene vs Cell Processor Developed by IBMMarket: national security science Budget: ~100 M$ Developed bySony, Toshiba and IBMMarket: VIDEOGAMESBudget: 500 M$ High performance computing is driven now by embedded systems(games, video, ....) → Science is a spin-off, at best ... XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Game Processors as Supercomputers ? Slide from CHEP'04 Dave McQueeneyIBM CTO US Federal XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CPU and FPGA paradigms merge Conventional CPU SIMD (single instruction – multiple data) CPU Register Wide Register Control Control ALU ALU ALU ALU ALU Configurable Instruction Set CPU Wide Register arithmeticresources ALU ALU ALU ALU ALU ALU Control PSM PSM PSM PSM PSM ALU ALU ALU ALU ALU ALU configurableconnectionfabric PSM PSM PSM PSM PSM ALU ALU ALU ALU ALU ALU XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Configurable Instruction Set Processor • Example Stretch S5xxx • Hybrid design: • conventional fixed instruction set part • plus configurable instruction set part • C/C++ compiler analyses the kernel of algorithms • generates custom instruction set • generates code to use it • The promise • easy of use of C/C++ • performance of an FPGA Stretch S5 engine Fabric is the keyword interconnected resources XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CPU and FPGA paradigms merge Unclear what the most suitablearchitecture will be The general trend howeverwill produce a lot ofinnovation in the years to come Essential will be availability of efficient development tools CPU Processorindustryworld view configurablelogic configurablelogic FPGAindustryworld view Moore will go on ! There are the technologies There are the markets Architectural changes ahead CPU CPU XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
Summary Substantial R&D needed • Self-triggered FEE: • autonomous hit detection, time-stamping with ns presision • sparsification, hit buffering, high output bandwidth • High bandwidth event building network • to cope with few 100 MHz interaction rate in p-p, p-A • likely be done in time slices or event slices • L1 processor farm • feasible with PC + FPGA + Moore (needed 2014) • but look beyond todays PC's and FPGA's • Efficient algorithms (109 tracks/sec) • co-design of critical detectors and tracking software Quitedifferentfrom thecurrentLHC styleelectronics RII3-CT-2004-506078 XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
The End Thanks for your attention XXXVI. Treffen Kernphysik, Schleching/Obb., Walter F.J. Müller, GSI
CBM Collaboration : 39+ institutions, 14+ countries China: Hua-Zhong Univ., Wuhan Croatia: RBI, Zagreb Cyprus: Nikosia Univ. Czech Republic: Czech Acad. Science, Rez Techn. Univ. Prague France: IReS Strasbourg Germany: Univ. Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst. Univ. Frankfurt Univ. Kaiserslautern Univ. Mannheim Univ. Marburg Univ. Münster FZ Rossendorf GSI Darmstadt Russia: CKBM, St. Petersburg IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov Inst., Moscow LHE, JINR Dubna LPP, JINR Dubna LIT, JINR Dubna LTP, JINR Dubna MEPhi, Moskau Obninsk State Univ. PNPI Gatchina SINP, Moscow State Univ. St. Petersburg Polytec. U. Spain: Santiago de Compostela Uni. Ukraine: Shevshenko Univ. , Kiev Hungaria: KFKI Budapest Eötvös Univ. Budapest Korea: Korea Univ. Seoul Pusan National Univ. Norway: Univ. Bergen Poland: Krakow Univ. Warsaw Univ. Silesia Univ. Katowice Portugal: LIP Coimbra Romania: NIPNE Bucharest membership applications in italic