arXiv Machine Learning

Memory Bandwidth, Not FLOPs: Profiling and Accelerating Query-Based Segmentation Decoders on Edge GPUs

The paper shows that query‑based segmentation decoders on edge GPUs are limited by memory bandwidth rather than FLOPs. Profiling reveals that non‑tensor‑core operations consume a large fraction of decoder time and bytes, saturating the DRAM bus. CompactInst mitigates this by using parameter‑free spatial pooling and a lightweight refinement head, achieving significant speedups on Jetson Orin Nano while maintaining accuracy.

arXiv Machine Learning
Sep 3

Unfolding the Leech Lattice: Fused Multi-Shell Decoding and VRAM Layouts for 2-Bit LLM Weights

The paper introduces a multi‑shell decoder for Leech‑lattice vector quantization, achieving the best reported 2‑bit quality under its evaluation protocol. It presents a GPU‑friendly layout that fuses dequantization with matrix‑vector multiplication, demonstrating significant speed and memory advantages over traditional one‑hot masks and other 4‑bit methods. Experiments show the new kernel outperforms baseline approaches across multiple model sizes, with measurable gains in throughput and reduced byte traffic.

By Pier-Jean Malandrino (Scub)
arXiv Machine Learning
Sep 23

Accelerating the Mitigation of LLM Inference Nondeterminism Across GPU Architectures

The paper addresses the problem of non‑deterministic outputs from large language models (LLMs) when run on different GPU architectures, caused by floating‑point non‑associativity and hardware‑dependent kernel choices. It proposes a set of fixed‑configuration fused‑upcast GEMM kernels that load 16‑bit weights, upcast to FP32, and perform IEEE‑754 compliant reductions in a problem‑shape‑dependent order, ensuring identical linear‑layer outputs across NVIDIA Ampere, Ada, and Hopper GPUs. The new approach achieves 1.17–3.1× faster end‑to‑end performance than existing solutions and halves weight‑memory traffic while maintaining cross‑architecture reproducibility.

By Liam Cooper, Shinnung Jeong, Hyeran Jeon, Jeffrey Young, Hyesoon Kim
arXiv AI
Oct 9

The Missing Fourth Term for the Emulation Tensor Memory Equilibrium (TME) Model: The Residue Deconstruction Cost

The paper identifies a missing cost term in the Tensor‑Memory Equilibrium (TME) model for emulating fp64 on GPUs: the per‑input deconstruction cost required before matrix multiplication can proceed. By adding this term and calibrating it against cuBLAS, the authors derive a closed‑form operational‑intensity threshold (OI*) below which emulation cannot match native fp64 performance. On an NVIDIA B300 GPU, this threshold is about 0.56 FLOP/B, limiting the speed‑ups of memory‑bound kernels such as GEMV, SpMV, and low‑batch GEMV to 0.3–0.9× native, and reducing the 7‑point stencil speed‑up from 3.1× to 1.8×, while dense GEMM remains unaffected.

By Harun Bayraktar, John Gunnels, Peter Caday
arXiv Machine Learning
Jun 15

Realizing Native INT8 Compute for Diffusion Transformers on Consumer GPUs: A Fused INT8 GEMM Kernel for Ideogram 4.0

arXiv:2606. 14598v1 Announce Type: new Abstract: Post-training INT8 (W8A8) quantization of diffusion transformers is widely deployed as a speed optimization, yet on consumer Ampere GPUs it is frequently slower than the FP8 and NF4 alternatives it is meant to beat.

By Ali Asaria, Tony Salomone, Deep Gandhi