Ahmer Nadeem Khan
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Warm-started higher order randomized SVD on GPUs for streaming tensor data

Developing warm-started randomized HOSVD algorithms optimized for GPUs to efficiently conduct lossy compression of streaming tensor data.

21% Fewer bytes than cold-start at tight tolerance
3.4× Warm-start, faster at every tolerance
16.7B Voxels across 3 scientific datasets

Overview

This project develops warm-started randomized higher-order SVD algorithms optimized for GPUs to efficiently compress and decompress streaming tensor data, for example the kind produced in massive scientific simulations (e.g. weather simulations). The goal is to produce error-controlled Tucker decompositions of streaming high-dimensional tensors ("snapshots") efficiently and independently to prepare for a compression pipeline, leveraging prior solutions to accelerate SVD on new data arrivals using stochastic methods.

Progress

June 2026

Adaptive error-bounded compression: warm vs cold (slides)

Adaptive L+S warm-started compressor with a pointwise maximum error guarantee and cost-optimal rank selection; benchmarked on Hurricane Isabel. Method extended to two static datasets.

May 2026

Compression fidelity on Hurricane Isabel (slides)

Compression fidelity analysis measuring PSNR and reconstruction quality across all 13 physical variables.

April 2026

Hurricane benchmark (slides)

Presentation on hurricane benchmark results and performance evaluation.

March 2026

Preliminary experiments (slides)

Began experimental validation on synthetic and real tensor streams. Initial benchmark comparisons with baseline methods and exploration of GPU kernel optimizations.

Feb 2026

Ideation phase and presentation (slides)

Initial conceptualization of the warm-started rHOSVD algorithm for streaming tensor decomposition.

Dataset Hurricane IsabelWRF weather NYXCosmology MirandaTurbulent mixing
Grid 100 × 500 × 500 × 48 512 × 512 × 512 384 × 384 × 256
Variables 13 6 7
Experiment warm + cold cold cold

The current CPU milestone is an adaptive, error-bounded compressor that stores each snapshot as a low-rank layer plus a sparse correction layer (Â = L + S), with a hard guarantee that the maximum elementwise error never exceeds a user tolerance τ. The cost-optimal rank is selected by minimizing a cost model objective function discretely, and on streaming data the previous snapshot's singular subspace is reused as a warm start, and the trailing optimal rank is used to minimize the search window, cutting time at every tolerance and, at tight tolerances on dense fields, also storing fewer bytes at higher fidelity. The method is evaluated on three scientific datasets: Hurricane Isabel (temporal), NYX (cosmology), and Miranda (turbulent mixing).

Warm-Start vs Cold-Start

Warm-start is faster at every tolerance; its storage and fidelity gains emerge only as the error tolerance tightens and the optimal rank climbs. Ranges span the four featured Isabel variables.

Hurricane Isabel
Warm-start advantage by tolerance: speedup, bytes saved, and PSNR gain; gains grow as tolerance tightens
Compression ratio per timestep, warm-start versus cold-start, Isabel wind field at tightest tolerance
Isabel warm vs cold: optimal rank and violation counts across 48 timesteps for the four variables

Static Datasets: NYX & Miranda

On non-temporal variables the compressor runs cold. NYX splits into three compressibility regimes; densities collapse to one rank, velocities are mid-rank, and temperature climbs steeply as the tolerance tightens. Miranda stays comfortably compressible across every field and tolerance.

NYX
NYX adaptive rank k-star per field and tolerance
Miranda
Miranda compression ratio per field and tolerance

Next Steps

  • GPU acceleration. Port the warm-started rSVD to GPU — the per-snapshot work is BLAS-3-bound and parallelises cleanly for streaming throughput.
  • Higher-order decomposition. Extend from per-snapshot matrix rSVD to warm-started Tucker / HOSVD across all tensor modes.
  • Compression backend. Replace the 12 B/entry sparse model with entropy-coded formats and a store-raw fallback, and benchmark end-to-end against SZ3.
  • Error analysis. Deterministic and probabilistic guarantees linking the tolerance to the selected rank and oversampling.