Torch Xpu Run

torch-xpu-run

Upstream PyTorch since 2.8 has a first-class torch.xpu namespace mirroring torch.cuda. Don't use intel-extension-for-pytorch (ipex) or ipex-llm — both are end-of-life (March 2026), upstream PyTorch supersedes them.

CUDA -> XPU code translation

Where to get PyTorch with XPU

Stock upstream PyTorch ships XPU support — no extra index needed. Verify: python3 -c 'import torch; print(torch.__version__)' — the version ends in +xpu when XPU support is present.

Three options:

1. Reuse a serving image — intel/vllm:*-xpu ships a working torch-xpu inside; start with --entrypoint /bin/bash.
2. Build a thin Dockerfile on ubuntu:24.04 or python:3.12-slim, pip install torch with XPU per https://pytorch.org/get-started/locally/.
3. Local venv — same install command, no container.

Launch with the GPU visible (see xpu-container-run for full flags):

docker run --rm -it \
    --device /dev/dri \
    --ipc=host \
    -e ZE_AFFINITY_MASK=0 \
    -e HF_TOKEN="$HF_TOKEN" \
    -v "$HOME/.cache/huggingface:/root/.cache/huggingface" \
    --entrypoint /bin/bash \
    <torch-xpu-image>

Quickstart

STOP — confirm before proceeding. Before installing packages or downloading weights, ask the user to confirm:

1. The model ID (and dtype if not bf16)
2. That installing packages (pip install torch transformers accelerate) and downloading multi-GB weights is acceptable

Do not run pip install, uv pip install, or model download commands until the user explicitly confirms. This is a hard requirement.

Check before installing. Always verify packages are already present before running pip install:

python3 -c "import transformers; print(transformers.__version__)" 2>&1 && \
python3 -c "import accelerate; print(accelerate.__version__)" 2>&1

Only install if the import check fails:

pip install --quiet --break-system-packages 'transformers>=4.46' accelerate

(--break-system-packages is needed under PEP 668 in Ubuntu 24.04+; omit in older images, or use a venv.)

from transformers import AutoConfig, AutoModelForCausalLM, AutoTokenizer
import torch

model_id = "Qwen/Qwen2.5-1.5B-Instruct"

# Fetch config first to apply pre-load patches.
cfg = AutoConfig.from_pretrained(model_id)

# Rope-scaling: older models omit the 'type' field required by
# Transformers 5.x; inject it to prevent a KeyError on load.
rope = getattr(cfg, "rope_scaling", None)
if isinstance(rope, dict) and "type" not in rope:
    rope["type"] = rope.get("rope_type", "linear")

tok = AutoTokenizer.from_pretrained(model_id)
# Many models ship without a pad token; set it to avoid
# 'does not have a padding token' on batched calls.
if tok.pad_token is None and tok.eos_token is not None:
    tok.pad_token = tok.eos_token

model = AutoModelForCausalLM.from_pretrained(
    model_id,
    config=cfg,
    dtype=torch.bfloat16,
    low_cpu_mem_usage=True,
    device_map="xpu",
)
inputs = tok("Tell me a joke.", return_tensors="pt").to("xpu")
out = model.generate(**inputs, max_new_tokens=64)
print(tok.decode(out[0], skip_special_tokens=True))

trust_remote_code: If the load raises unrecognized configuration class or the model card shows config.auto_map, add trust_remote_code=True to the from_pretrained calls — but warn the user first, since this runs the repo's custom Python modules.

Preflight checklist — settings to apply when a load fails or is new

Apply these in response to specific load errors, or as a starting point for a model you haven't run on XPU before. Each setting addresses a named signal.

1. low_cpu_mem_usage=True — avoids loading all weights to CPU RAM before copying to XPU (peaks at 2× model size). Apply when you see a CPU OOM before the XPU load completes.
2. dtype=torch.bfloat16 — default; halves memory vs fp32. See "Pick the right dtype" below.
3. tokenizer.pad_token = tokenizer.eos_token — apply when a batched call raises does not have a padding token. Many models (GPT-2, Llama, Qwen) ship without one.
4. Normalise config.rope_scaling — apply when load raises a KeyError on rope_scaling['type']. Inject type = rope_scaling.get( 'rope_type', 'linear') before calling from_pretrained. See xpu-transformers-compat for the full set of Transformers 5.x shims.
5. Warn on model size — before a long checkpoint download, check whether the model fits the available VRAM; see model-can-it-fit.
6. Pick the correct loader class — AutoModelForCausalLM for decoder LLMs; vision / audio / seq2seq / reward / time-series need different classes. See xpu-model-type-detect.

Pick the right dtype

• bfloat16 — default. Battlemage / Arc Pro have full hardware support; float16 works for most ops but a small set degrades or falls back to slow paths.
• float32 — diagnostic fallback when bf16 fails to load (rare). Halves memory; not for production.

For quantized models on XPU:

• Intel AutoRound (Int4 / Int3 / Int2) is the recommended algorithm. Exports as AutoAWQ-style or AutoGPTQ-style packing; runtimes auto-detect via quantization_config.quant_method=auto-round.
• AutoAWQ — loads through Transformers; verify output content, not just successful load.
• GPTQ — regressed in vLLM v0.19.0 (vLLM #39474); pin v0.18.x or use AutoRound's GPTQ-format export.
• bitsandbytes — limited XPU support; prefer AutoRound.

For full per-quant CLI / env vars when serving, see vllm-xpu-run Quantization section.

Multi-GPU on one host

Single-process, multiple XPUs (device_map)

Make both XPUs visible (-e ZE_AFFINITY_MASK=0,1), then:

model = AutoModelForCausalLM.from_pretrained(
    model_id, dtype=torch.bfloat16, device_map="auto"
)

Accelerate prints layer placement; verify both xpu:0 and xpu:1.

One process per XPU (DDP / multiple servers)

import torch.distributed as dist
dist.init_process_group(backend="xccl")    # upstream XPU collective backend

Backend is "xccl", not "nccl". The older "ccl" value targets the deprecated torch_ccl plugin and will fail with current upstream PyTorch. Launch via torchrun --nproc_per_node=N inside a container that sees all XPUs, or one container per XPU with ZE_AFFINITY_MASK=N.

Verifying it ran on XPU

print(model.device)                        # xpu:0
print(next(model.parameters()).device)     # xpu:0
print(torch.xpu.memory_allocated(0))       # > 0 after load

From the host while generating:

xpu-smi dump -d 0 -m 5,18 -i 1

Memory should climb when the model loads. If it doesn't, the model is on CPU.

Common errors

• Cannot find any XPU devices -> container missing GPU access; see xpu-container-run.
• Torch not compiled with XPU enabled -> wrong PyTorch build. The image must have torch.__version__ ending in +xpu.
• OSError: Tokenizer ... requires Hub access -> set HF_TOKEN or huggingface-cli login.
• CUDA error: ... literal substring inside an XPU workload -> a third-party library (older bitsandbytes, flash-attn, xformers) is hard-coded to CUDA. Use an XPU-aware fork or fall back to pure PyTorch (Transformers' attn_implementation="sdpa" covers the common attention case).
• Expected one of cpu, cuda, ... device type at start of device string: xpu -> very old transformers (<4.46) or accelerate (<0.34). Upgrade.
• model type '<X>' Transformers does not recognize -> installed transformers is older than the model architecture. Upgrade or pin per the model card; install from source if needed (pip install git+https://github.com/huggingface/transformers.git).
• float16 not supported on this device -> switch to dtype=torch.bfloat16.
• Unknown scheme for proxy URL ... 'socks://...' -> httpx (used by huggingface_hub) doesn't support SOCKS proxies without the optional transport. Fix: pip install httpx[socks], or unset the proxy for that session: unset ALL_PROXY all_proxy. If the model is already cached, HF_HUB_OFFLINE=1 also bypasses the issue.
• Hang at "Loading checkpoint shards" -> usually cold cache + slow network. Pre-hf download into ~/.cache/huggingface.
• Hang on first generate() -> Triton kernel compile is cold. Set TRITON_CACHE_DIR to a persistent volume.

Env vars

What this skill does NOT cover

• vLLM serving -> vllm-xpu-run.
• SGLang serving -> sglang-xpu-run.
• Per-model quant gotchas (AWQ quirks, GPTQ kernel coverage) — go in fix-level skills.
• Profiling and kernel-level fixes — out of scope.

References

• Upstream PyTorch XPU notes: https://docs.pytorch.org/docs/stable/notes/get_start_xpu.html
• Intel GPU/CPU enabling status, H1 2026: https://dev-discuss.pytorch.org/t/intel-gpu-cpu-enabling-status-and-feature-plan-2026-h1-update/3320
• HF Accelerate XPU: https://huggingface.co/docs/accelerate/en/usage_guides/xpu
• Intel AutoRound: https://github.com/intel/auto-round