Spark-X2.5-4B — Q4_0_ROCMFP4_STRIX_LEAN (GGUF)

Quantization of XHToken/Spark-X2.5-4B to the ROCmFPX GGUF family, tuned for AMD Strix Halo (Ryzen AI Max / gfx1151).

This GGUF runs ONLY on the ROCmFPX llama.cpp fork — with spark2_5 architecture support (fork main @ c49ebdb + the port patch, see below). Stock llama.cpp, Ollama, and LM Studio cannot load it. The HF/GGUF automated parser does not know the ROCmFPX quant enums and may mislabel this file as "F16" — the real format is Q4_0_ROCMFP4_STRIX_LEAN (4.39 BPW).

Files

File Size Notes
Spark-X2.5-4B-Q4_0_ROCMFP4_STRIX_LEAN.gguf 2.26 GB (2,260,702,112 bytes) single file, chat template embedded
Spark-X2.5-4B-Q4_0_ROCMFP4_STRIX_LEAN.imatrix 3.57 MB importance matrix used for this quant (see below)

SHA256 (Spark-X2.5-4B-Q4_0_ROCMFP4_STRIX_LEAN.gguf): f3c3a526d5ef7b8e249ca1b1a092878d047bfefc9e3cb432d21643452cf94699

Quantization details

  • Source: official BF16 GGUF XHToken/Spark-X2.5-4B-GGUF (Spark-X2.5-4B.gguf, 8.23 GB, verified true BF16)
  • Preset: Q4_0_ROCMFP4_STRIX_LEAN — 2150.83 MiB, 4.39 bits per weight (smallest-footprint Strix Halo recipe)
  • Tensor census (290/290 tensors, 1:1 with source):
    • Q4_0_ROCMFP4 ×36 — fused attn_qkv of every block (dual per-16 scale, Strix attn-K/V quality)
    • Q4_0_ROCMFP4_FAST ×180 — attn_gate, attn_output, ffn_gate/up/down
    • F32 ×73 — all norms
    • Q5_K ×1 — token_embd (tied embeddings)
  • Importance matrix: self-generated (the publisher ships none). llama-imatrix over ~29K tokens (57 chunks × 512) sampled proportionally from the eaddario/imatrix-calibration corpus (MIT) — tools_medium (tool-use/agentic prompts), code_medium (code instructions from Magicoder-Evol-Instruct-110K / OpenCoder / McEval) and combined_th_small (Thai) — computed on an F16 copy of the official BF16 GGUF. The .imatrix file is included for reproducibility.

Base model

Model Spark-X2.5-4B (dense 4.112B)
Architecture spark2_5 — hybrid attention 3×SWA(window 512) : 1×full, GQA 16/4 heads, head_dim 256
Context 1,048,576 tokens (max_position_embeddings)
Vocabulary 131,072 (tied embeddings), BPE (tokenizer.ggml.pre = spark2_5)
Behavior thinking model — emits <think>…</think> reasoning before the answer
License Apache-2.0 (inherited from base)

Usage (Strix Halo, gfx1151)

Build the ROCmFPX server image from the fork with the spark2_5 patch, then:

docker run -d --name rocmfpx-serve --restart unless-stopped \
  --device /dev/kfd --device /dev/dri \
  --group-add "$(getent group render | cut -d: -f3)" \
  --group-add "$(getent group video  | cut -d: -f3)" \
  -p 8080:8080 -v /models:/models:ro \
  -e HSA_OVERRIDE_GFX_VERSION=11.5.1 \
  -e GGML_HIP_ENABLE_UNIFIED_MEMORY=1 \
  rocmfpx:server \
  -m /models/Spark-X2.5-4B-Q4_0_ROCMFP4_STRIX_LEAN.gguf \
  -ngl 999 -fa on -c 32768 -b 512 -ub 512 \
  -ctk q8_0 -ctv q8_0 \
  --jinja

GET :8080/health when ready. The model has no MTP/draft head — do not pass --spec-* flags. Weights are ~2.3 GB and SWA keeps the KV cache small, so this fits Strix Halo's unified memory comfortably. Expect fast decode via the HIP/Vulkan FP4 paths (CPU-only hosts will be slow — the format targets the GPU).

Verification

  • The artifact was verified end-to-end on the quantize box: loads and generates coherently through the ported spark2_5 graph on both the x86_64 ROCmFPX binaries (QEMU) and an aarch64 CPU build — e.g. correct <think>-style reasoning and answers ("The capital of France is Paris.").
  • Confirmed working on real hardware: runs on an AMD Strix Point iGPU via the ROCmFPX fork. Strix Halo (gfx1151) throughput numbers are not yet measured.

Acknowledgements

  • Base model: XHToken/Spark-X2.5-4B (Apache-2.0)
  • Format & runtime: ROCmFPX llama.cpp fork
  • spark2_5 support in the fork comes from an upstream llama.cpp port (PR #27868, b10828) — patch against fork c49ebdb available on request
Downloads last month
65
GGUF
Model size
4B params
Architecture
spark2_5
Hardware compatibility
Log In to add your hardware

4-bit

Inference Providers NEW
This model isn't deployed by any Inference Provider. 🙋 Ask for provider support

Model tree for nanash66/Spark-X2.5-4B-ROCmFP4-STRIX_LEAN-GGUF

Quantized
(41)
this model