Kumar et al. (2024) — ARXIV-2411.04330

Key takeaways

  • Standard scaling laws are silent about numerical precision, which is strange given that precision decides both training cost and serving cost. This fits precision-aware laws for both.
  • The training-side idea: low precision reduces the model’s effective parameter count, which makes the extra loss from training in low precision predictable rather than empirical, and lets the law price parts of a model held at different precisions.
  • The inference-side result is the counter-intuitive one: degradation from post-training quantization increases with how much data the model was trained on, to the point where additional pretraining data becomes actively harmful if the model will be quantized afterwards. More training makes a model less robust to being compressed.
  • Both are unified into a single functional form covering pre- and post-training quantization, fit on over 465 pretraining runs and validated up to 1.7B parameters and 26B tokens.
  • A practical suggestion falls out: training larger models in lower precision may be compute-optimal.

Standing in the anthology

Filed because two models the record holds ship precision decisions this paper’s framework is about, and neither note explains why they are choices rather than implementation details: LIT-139’s DeepSeek-V4 does FP4 quantization-aware training on the expert weights and the indexer’s query-key path, and Kimi K3 releases in MXFP4.

The inference result is the one a reader should carry: if a model is going to be quantized for serving, the pretraining budget and the quantization plan are not independent decisions, and the usual instinct — train on more data, it can only help — is wrong past a point this paper can locate. Its own limit is scale; the fits stop at 1.7B and 26B tokens, far below everything that ships FP4 today.

The practice is SOTA-160, Proposed. The inference result is what it recommends: if a model will be served quantized, the token budget and the quantization plan are one decision. It is Proposed because the fits stop at 1.7B and 26B tokens, far below everything that ships FP4 — the effect is well measured where it was measured, and the regime it matters most in is not that regime.