Anthony Wang 5c965fd8ca llama-quant : fix 4D tensor quantization using ggml_nrows() and name-based expert detection (#30820)
* llama-quant : fix quantizing 4D tensors

nrows_total was ne[1]*ne[2], so for a 4D tensor only the first ne[2]
slices were quantized and the rest of the rows were dropped. Use
ggml_nrows(tensor) to count all rows, including ne[3].

Fixes #29916

* llama-quant : detect expert tensors by name and fix imatrix size for 4D tensors

The MXFP4_MOE path used ne[2] > 1 to detect MoE expert tensors. This is
wrong for non-expert tensors with 3 or more dims, e.g. MLA projections
(BailingMoE3) and 4D conv kernels. Use the tensor name instead: all
tensors used by GGML_OP_MUL_MAT_ID are named *_exps or *_chexps. This
also removes the BailingMoE3 special case.

The imatrix holds one vector of ne[0] values per 2D slice, so the
expected size is ne[0]*ne[2]*ne[3], not ne[0]*ne[2]. This matches how
the imatrix is indexed per row for 4D tensors in llama_tensor_quantize_impl.

Assisted-by: Claude Opus 5.5
2026-10-25 13:28:38 +02:00
2026-10-25 09:43:51 +08:00
2026-10-23 07:46:53 -07:00
2026-10-25 09:43:51 +08:00
2026-06-12 15:53:26 +02:00
2026-10-17 02:11:56 +02:00
2026-02-02 08:38:55 +02:00

llama.cpp

llama

Quick start

A few options to get llama.cpp installed on your machine:

# curl
curl -LsSf https://llama.app/install.sh | sh

# powershell
irm https://llama.app/install.ps1 | iex

Once installed:

# Download and run a model directly from Hugging Face
llama cli -hf ggml-org/Qwen3.5-0.8B-GGUF

# Launch OpenAI-compatible API server
llama serve -hf ggml-org/Qwen3.5-0.8B-GGUF
VLM session with `llama cli` VLM session with llama cli Built-in web UI against `llama serve` running Qwen 3.6 Built-in web UI against llama serve

Description

The main goal of llama.cpp is to enable LLM (and VLM) inference with minimal setup and state-of-the-art performance on a wide range of hardware - locally and in the cloud.

  • Plain C/C++ implementation without any dependencies
  • Apple silicon is a first-class citizen - optimized via ARM NEON, Accelerate and Metal frameworks
  • AVX, AVX2, AVX512 and AMX support for x86 architectures
  • RVV, ZVFH, ZFH, ZICBOP and ZIHINTPAUSE support for RISC-V architectures
  • 1.5-bit, 2-bit, 3-bit, 4-bit, 5-bit, 6-bit, and 8-bit integer quantization for faster inference and reduced memory use
  • Custom CUDA kernels for running LLMs on NVIDIA GPUs (support for AMD GPUs via HIP and Moore Threads GPUs via MUSA)
  • Vulkan and SYCL backend support
  • CPU+GPU hybrid inference to partially accelerate models larger than the total VRAM capacity

The llama.cpp project is build on top of the ggml library.

Supported backends

Backend Target devices
BLAS All
BLIS All
CANN Ascend NPU
CUDA Nvidia GPU
HIP AMD GPU
Hexagon Snapdragon
IBM zDNN IBM Z & LinuxONE
MUSA Moore Threads GPU
Metal Apple Silicon
OpenCL Adreno GPU
OpenVINO [In Progress] Intel CPUs, GPUs, and NPUs
RPC All
SYCL Intel GPU
VirtGPU VirtGPU APIR
Vulkan GPU
WebGPU All
ZenDNN AMD CPU

Documentation

Tools

Development

Contributing

  • Contributors can open PRs
  • Collaborators will be invited based on contributions
  • Maintainers can push to branches in the llama.cpp repo and merge PRs into the master branch
  • Any help with managing issues, PRs and projects is very appreciated!
  • Read the CONTRIBUTING.md for more information

Acknowledgements

  • yhirose/cpp-httplib - Single-header HTTP server, used by llama-server - MIT license
  • nothings/stb - Single-header image format decoder, used by multimodal subsystem - Public domain
  • nlohmann/json - Single-header JSON library, used by various tools/examples - MIT License
  • mackron/miniaudio - Single-header audio format decoder, used by multimodal subsystem - Public domain
  • sheredom/subprocess.h - Single-header process launching solution for C and C++ - Public domain
Languages
C++ 56.2%
C 15.5%
Python 7.5%
Cuda 5.2%
TypeScript 4.4%
Other 11%