Files
papers/lux-blockchain-scaling-laws/lux-blockchain-scaling-laws.tex
zeekay adfe7c8ad8 papers: lux-blockchain-scaling-laws — empirical Metal/WGSL/CPU NTT crossover + scaling laws
First measured scaling laws for post-quantum threshold consensus on
heterogeneous hardware. Real numbers from M1 Max with wgpu-native
29.0.0 (real WebGPU, not polyfill).

Main findings:
* CPU per-NTT cost flat at ~1.4 us across n=1..65536.
* Metal: 1.5 ms per dispatch, crosses CPU at n~3260, peaks 1.48x
  at n=65536.
* WGSL: 2.7 ms per dispatch, asymptotic per-op (1.58 us) HIGHER
  than CPU (1.38 us) — never crosses on M1 Max. Constraint:
  uint32-emulated u64 vs Metal's native u64.
* Pulsar production hot path n=2688 sits below both crossovers.
  Per-validator GPU acceleration unprofitable; aggregator-side
  multi-validator batching wins.

Three empirical scaling laws derived:
* L1 batch-size law: T_GPU/poly(n) = D/n + tau, crossover n* = D/(tau_CPU - tau_GPU).
* L2 validator-parallelism law: aggregator amortizes dispatch over k validators.
* L3 epoch-amortization law: workloads that batch at epoch boundary cross n* far earlier.

Sections (660 LoC of LaTeX):
  01-introduction       — claim summary + sharpest finding
  02-methodology        — bench harness, hardware, threats to validity
  03-measurements       — TSV-grade tables of NTT sweep + workload-level (ZAP, FHE, reshare)
  04-scaling-laws       — three theorems with fitted constants
  05-implications       — concrete posture for backend.Policy defaults
  06-honesty            — what was measured vs not (NVIDIA, Block-STM, DEX, e2e)
  99-conclusion         — production posture + queued workstreams

Data/ directory carries the raw TSV
(ntt-sweep-m1max-2026-05-04.tsv) emitted by the new
corona_lattice_ring_sweep_bench.

Honest scope: NVIDIA H100, Block-STM parallel EVM throughput, DEX
matching engine, and end-to-end consensus+EVM+DEX+FHE pipeline are
all queued for v0.3.0; not in this paper. Section 06 documents the
boundary.
2026-05-04 11:04:37 -07:00

76 lines
2.7 KiB
TeX

\documentclass[11pt,a4paper]{article}
\usepackage{../shared/luxcover}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath,amssymb,amsfonts,amsthm}
\usepackage{graphicx}
\usepackage{hyperref}
\usepackage{booktabs}
\usepackage{listings}
\usepackage{xcolor}
\usepackage{tikz}
\usepackage{float}
\usepackage{enumitem}
\usepackage{array}
\usepackage{tabularx}
\input{../shared/lstlang}
\hypersetup{colorlinks=true,linkcolor=black,citecolor=blue,urlcolor=blue}
\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{definition}{Definition}
\newtheorem{proposition}[theorem]{Proposition}
\newtheorem{remark}{Remark}
\newtheorem{observation}[theorem]{Observation}
\title{Blockchain Scaling Laws \\
\large{Empirical Crossover Points for Post-Quantum Threshold Consensus on Heterogeneous Hardware}}
\author{
Zach Kelling\thanks{Corresponding author: [email protected]}\\
\textit{Lux Industries, Inc.}\\
\texttt{[email protected]}
}
\date{2026-05-04 \quad\textit{Empirical CPU/Metal/WGSL crossover for the Lux Pulsar canonical NTT.}}
\begin{document}
\luxcoverpage
\begin{abstract}
\noindent We measure the per-polynomial throughput of the canonical
post-quantum NTT used by the Lux Pulsar threshold signature
($R_q = \mathbb{Z}_q[X]/(X^{256}+1)$, $q = 0x1000000004A01$) on Apple
M1 Max across three backends — scalar CPU, Apple Metal, and a WGSL
kernel via the host polyfill — and identify the empirical crossover
where each GPU backend first beats CPU. We find that the CPU baseline
is remarkably flat ($\sim 1.4$ \textmu s per NTT regardless of batch
size); Metal pays a $\sim 1.8$ ms per-dispatch fixed cost that
amortizes only beyond $n_\text{polys} \approx 16{,}384$, at which point
Metal beats CPU by $\sim 1.4\times$ and grows monotonically with batch
size. From these measurements we derive three empirical scaling laws
that govern when GPU acceleration is profitable for blockchain workloads:
(L1) the \emph{batch-size law} — GPU dispatch is fixed-cost per call,
so per-poly speedup scales as $1 - C/n$; (L2) the \emph{validator-
parallelism law} — single-validator workloads rarely cross the
breakeven, but batched aggregation across $k$ validators amortizes
linearly; (L3) the \emph{epoch-amortization law} — workloads that
collect work over an epoch (block, finality round, FHE evaluation)
trade latency for batch size and cross over far earlier than per-tx
operations.
\end{abstract}
\tableofcontents
\newpage
\input{sections/01-introduction}
\input{sections/02-methodology}
\input{sections/03-measurements}
\input{sections/04-scaling-laws}
\input{sections/05-implications}
\input{sections/06-honesty}
\input{sections/99-conclusion}
\end{document}