← Back
Home › Systems › Simulation and scientific computing

physics-daq

particle physics trigger and data acquisition

CERN LHC

SystemTechniques · 9Primitives · 40 physics-daq Clock synchronizationdistributed · medium: Estimate a clock's offset from four timestamps, filter out queueing noise, and steer the clock smoothly; NTP gets about a millisecond, PTP with hardware timestamps under a microsecond.›Fpga dataflow pipelineshardware-os · medium: Fully pipelined fixed-latency FPGA logic: initiation interval, HLS, BRAM and DSP budgetingGradient-boosted decision trees (GB…machine-learning · medium: Add small regression trees one at a time, each fitted to the loss gradient; histogram splits over 256 bins make it the strongest tabular default.›Hough transformrobotics · medium: Vote in parameter space to detect lines, circles and particle tracksColumnar storagestorage · medium: Store each column contiguously so analytic scans read only the columns they need, compress well and run as tight SIMD loops.›Instruction schedulingcompilers · medium: List scheduling over dependence DAGs with latency models; software pipelining of loopsStatic timing analysishardware-os · medium: Propagate latest/earliest arrival forward and required times backward through a DAG; slack = required - arrival, and the minimum-slack path is the critical one.›LZ4compression · low: Byte-aligned LZ77 with no entropy stage; compresses at hundreds of MB/s and decompresses at several GB/s per core, for when speed beats ratio.›SPSC ring bufferdata-structures · low: Bounded wait-free queue for exactly one producer and one consumer thread, built from an array and two indices with acquire/release ordering.›Deterministic fixed-point mathgame-networking · low: Bit-identical simulation math across CPUs, compilers and builds: integer fixed-point formats, the float traps (FMA, x87, fast-math, libm), deterministic trig, sqrt and RNG.›Buffer pools for zero-allocation I/Ohardware-os · low: Preallocate a fixed set of aligned I/O buffers and recycle them through a free list, so the hot path never mallocs, faults or unmaps. The bounded count doubles as back pressure.›CRC32C checksumshardware-os · low: The Castagnoli CRC-32 with dedicated instructions on x86 (SSE4.2) and ARMv8. It is the standard fast integrity check for storage blocks, logs and network frames.›Weight quantizationml-training · low: Store weights as 8/4-bit integers with per-group scales; decode is memory-bound, so 4-bit weights give about 3-4x tokens/s and fit 4x larger models.›Kernel-bypass networkingnetworking · low: User space (DPDK, AF_XDP) or an in-driver eBPF hook (XDP) handles packets straight from NIC rings, skipping sockets, for 10-40 Mpps per core.›Rdmanetworking · low: RDMA verbs over InfiniBand/RoCE: queue pairs, memory registration, one-sided opsKalman filterrobotics · low: Optimal recursive estimator for a linear system with Gaussian noise: fuses a motion model with noisy measurements into a state estimate plus its covariance.›Zero suppressionsignal-processing · low: Drop samples under threshold at readout and encode sparse hits with addressesPID controllerrobotics · low: Drive a measured value to a setpoint with three terms on the error: proportional, integral, derivative. The default feedback loop for motors, heaters, drones and gimbals.›Phase-locked loop (digital)signal-processing · low: Feedback loop that locks a local oscillator to the phase and frequency of an input tone; the core of carrier recovery, clock recovery and GNSS tracking.›Robust statisticsstatistics · low: Location and scale estimates (median, MAD, trimmed mean, Huber M-estimator) that stay correct when a minority of the data is garbage.›Quantile sketchesdata-structures · low: Mergeable quantile sketches: t-digest, DDSketch, HDR histogramsLoss functionsmachine-learning · low: The scalar a model minimizes: cross-entropy for classes and tokens, MSE or Huber for values, each with a stable form and simple gradient.›Regularizationmachine-learning · low: Techniques that trade training fit for generalization: weight decay, dropout, early stopping, label smoothing and data mixing, with the exact update rules and defaults.›+ 2 more techniques+ 24 more primitives

Similar systems

Share the most building blocks with this one.