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Environment:Bitsandbytes foundation Bitsandbytes XPU SYCL Runtime

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Knowledge Sources
Domains Infrastructure, XPU_Backend, SYCL
Last Updated 2026-02-07 14:00 GMT

Overview

Intel XPU SYCL runtime environment for running bitsandbytes quantization operations on Intel discrete GPUs using oneAPI/SYCL.

Description

This environment provides the Intel XPU GPU-accelerated context for running bitsandbytes operations on Intel discrete and integrated GPUs. It uses a three-tier dispatch strategy: (1) SYCL native kernels compiled via CMake with -DCOMPUTE_BACKEND=xpu for dequantize_4bit, dequantize_blockwise, and gemv_4bit; (2) Triton kernels for quantize_blockwise, quantize_4bit, and optimizer operations; (3) PyTorch fallback when neither SYCL nor Triton is available. The XPU backend requires Intel oneAPI toolkit 2025.1.3 and is detected via torch._C._has_xpu.

Usage

Use this environment for quantization and dequantization on Intel GPUs including 4-bit inference, blockwise dequantization, and 4-bit GEMV. The backend is automatically detected when an Intel XPU device is available in PyTorch.

System Requirements

Category Requirement Notes
Hardware Intel discrete GPU (Arc, Data Center Max, Flex) Intel XPU-capable device
OS Linux x86-64 (glibc >= 2.34), Windows x86-64 Ubuntu 22.04+ recommended
oneAPI Toolkit 2025.1.3 Intel Deep Learning Essentials
Python >= 3.10 From pyproject.toml
PyTorch >= 2.3, < 3 (>= 2.9 for int8_linear_matmul) torch._C._has_xpu must be True

Dependencies

System Packages

  • Intel oneAPI Base Toolkit 2025.1.3
  • SYCL runtime (libsycl.so)
  • Intel GPU drivers

Python Packages

  • `torch` >= 2.3, < 3
  • `intel_extension_for_pytorch` (optional, for extended XPU support)
  • `numpy` >= 1.17
  • `packaging` >= 20.9

Build Requirements (for SYCL kernels)

  • CMake with -DCOMPUTE_BACKEND=xpu
  • Docker image: intel/deep-learning-essentials:2025.1.3-0-devel-ubuntu22.04 (Linux)
  • Windows: Intel Deep Learning Essentials 2025.1.3 + Intel oneAPI setvars.bat

Credentials

No secrets or credentials required. The XPU backend is detected via PyTorch's built-in XPU device support.

Quick Install

# Install with Intel XPU support
pip install bitsandbytes

# Or build from source with SYCL kernels:
cmake -DCOMPUTE_BACKEND=xpu -S . -B build
cmake --build build
pip install -e .

# Verify XPU detection
python -c "import torch; print(torch.xpu.is_available())"
python -m bitsandbytes

Code Evidence

XPU backend detection from `bitsandbytes/cextension.py`:

elif torch._C._has_xpu:
    BNB_BACKEND = "XPU"

Three-tier dispatch strategy from `bitsandbytes/backends/xpu/ops.py`:

# Tier 1: SYCL native library (preferred)
@register_kernel("bitsandbytes::dequantize_4bit", "xpu")
def _(A, absmax, blocksize, quant_type, shape, dtype):
    # Uses compiled SYCL kernels via native library

# Tier 2: Triton kernels (fallback)
# Used for quantize_blockwise, quantize_4bit, optimizer ops

# Tier 3: PyTorch default (final fallback)
# Logged warning when neither SYCL nor Triton available

SYCL kernel headers from `csrc/xpu_kernels.h`:

#include <sycl/sycl.hpp>
// SYCL_EXTERNAL template kernel definitions

Common Errors

Error Message Cause Solution
`torch._C._has_xpu` is False Intel XPU support not available in PyTorch Install PyTorch with XPU support or intel_extension_for_pytorch
SYCL native library not found Built without -DCOMPUTE_BACKEND=xpu Rebuild with CMake XPU backend flag or use Triton fallback
int8_linear_matmul not available PyTorch < 2.9 Upgrade PyTorch to 2.9+ for torch._int_mm support on XPU

Compatibility Notes

  • Quantization types: Both NF4 and FP4 are supported.
  • Data types: Supports float16, bfloat16, and float32.
  • SYCL kernels: Provide best performance but require building from source with CMake.
  • Triton fallback: Available for most operations when SYCL native library is not present.
  • PyTorch >= 2.9: Required for INT8 linear matmul via torch._int_mm.
  • glibc >= 2.34: Required on Linux (Ubuntu 22.04+).

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