The llama.cpp project released build b10534, which introduces hardware-specific switch points to tune the crossover between vector and tensor-core paths during quantized decoding on CUDA.
- The release adds runtime configuration via GGML_CUDA_MMVQ_MAX to adjust the batch size threshold where the kernel switches from mul_mat_vec_q to MMQ.
- Specific switch point values are now included for Blackwell, DGX Spark, and Ada architectures, reducing reliance on environment variables.
- Lowering this threshold routes larger batches to the int8 MMQ tensor-core path, yielding a measured 23-41% speedup at batch size 8 on RTX 5090 for Q4_K dense models.
- The update includes binaries for macOS, Linux, Windows, Android, and openEuler across CPU, CUDA, Vulkan, ROCm, OpenVINO, and SYCL backends.
This change improves inference performance on modern NVIDIA GPUs by automatically selecting the most efficient kernel path based on batch size and hardware capabilities.