Maswali yanayounganishwa na mwongozo · Kati Kiwango

Maswali ya Usambamba wa Data

Pitia modeli zilizorudiwa, usawazishaji wa gradient, ukubwa wa kundi, gharama za mawasiliano, na mipaka ya kuongeza mafunzo kati ya wafanyakazi.

Njia za mwongozo zinazohusianaUsambamba wa data
Swali 1 ya 8

Katika ulinganifu wa kawaida wa data, kila GPU inashikilia nini?

Hakiki kila swali8 maswali

Majibu na maelezo huonekana unapojibu maswali.

  1. Katika ulinganifu wa kawaida wa data, kila GPU inashikilia nini?
    • Nakala kamili ya mfano, kusindika kipande tofauti cha kundi
    • Kipande tofauti cha tabaka za mfano
    • Hali ya kiboreshaji pekee, yenye uzani uliohifadhiwa katikati
    • Toleo lililobanwa la muundo na vigezo vichache
  2. Ni operesheni gani ya mawasiliano huweka nakala za mfano katika kusawazisha kila hatua?
    • Matangazo, ambayo hunakili data moja ya GPU kwa wengine wote
    • Punguza yote, ambayo ni wastani wa gradient kwenye GPU zote
    • Tawanya, ambayo inagawanya data kati ya GPU
    • Hakuna mawasiliano yanayohitajika kati ya GPU
  3. What memory limit remains in plain data parallelism?
    • The full model is sharded automatically across the GPUs
    • Only the input batch uses device memory
    • Each GPU keeps model parameters and optimizer state replicated, limiting the model size that fits
    • Each worker stores different model layers by default
  4. Which factors does NCCL use when selecting collective algorithms?
    • Only the random seed and learning rate
    • Only the total number of model parameters
    • The optimizer type and validation score
    • Message size and topology
  5. Je, PyTorch DistributedDataParallel inafichaje utulivu wa mawasiliano?
    • Kwa mwingiliano wa upinde rangi punguza kwa pasi inayoendelea ya kurudi nyuma
    • Kwa kuruka usawazishaji wa upinde rangi kwenye hatua zinazopishana
    • Kwa kubana gradients zote hadi nambari moja
    • Kwa kuendesha pasi ya mbele kwenye CPU
  6. With equal local batch size B on each of W data-parallel workers, what is the global batch for one synchronized step?
    • B divided by W
    • B multiplied by W, before any gradient-accumulation factor
    • Always exactly W samples
    • The model parameter count divided by B
  7. Why may adding more data-parallel GPUs fail to increase throughput proportionally?
    • All-reduce makes model parameters disappear
    • The model is copied only to one worker
    • Gradient communication, data loading, and synchronization add overhead
    • More workers always reduce the global batch to zero
  8. What does gradient accumulation let a data-parallel training loop do?
    • Shard parameters automatically across all workers
    • Skip forward and backward computation
    • Replace the model with an all-reduce operation
    • Combine gradients from multiple microbatches before an optimizer update