This repo contains an ik_llama-compatible DFlash draft GGUF converted from z-lab/Qwen3.5-35B-A3B-DFlash, carrying the per-layer sliding-window attention (SWA) pattern.

This is not a standalone chat model. Use it as a --model-draft file next to a matching Qwen3.5-35B-A3B target GGUF, with DFlash speculative decoding.

Sliding-window attention

The draft is sliding-window on every layer except a final full-attention (global) layer: sliding_window_pattern = [true, true, true, true, true, false], sliding_window = 4096.

Files

File	Quant	Draft window
`Qwen3.5-35B-A3B-DFlash-SWA-ik_llama-Q8_0.gguf`	Q8_0	4096 (5 sliding + 1 global)

Use

bash

llama-server \
  -m /path/to/Qwen3.5-35B-A3B-<quant>.gguf \
  --model-draft /path/to/Qwen3.5-35B-A3B-DFlash-SWA-ik_llama-Q8_0.gguf \
  --spec-type dflash:n_max=4,cross_ctx=8192 \
  -c 8192

SWA only engages once the DFlash cross-context exceeds the 4096 window, so set cross_ctx above the window for long-context prompts (the default 512 does not grow with -c).

Validation (RTX 4070, ik_llama DFlash SWA branch)

Draft acceptance and throughput versus the same draft run with full attention, as the prompt overflows the 4096 window, where clip = (prompt - 4096) / prompt:

prompt tok	clip	accept, full-attn	accept, SWA	acceptance gain	tok/s change
37	0%	36.1%	39.2%	+3.0 pp	+6.8%
5613	27%	28.4%	28.6%	+0.2 pp	-1.1%
8044	49%	22.3%	27.7%	+5.4 pp	+9.9%
11005	63%	15.9%	26.4%	+10.5 pp	+23%
19946	80%	5.5%	23.0%	+17.4 pp	+44%

The benefit grows with how far the prompt overflows the window and does not saturate.

Conversion

Converted from z-lab/Qwen3.5-35B-A3B-DFlash with ik_llama's convert_hf_to_gguf.py DFlash draft converter (sliding-window support branch), then quantized to Q8_0. The per-layer SWA pattern is taken from the source layer_types. Conversion requires a --target-model-dir containing the target tokenizer merges.

ji-farthing/Qwen3.5-35B-A3B-DFlash-SWA-ik-llama-GGUF

Qwen3.5-35B-A3B DFlash SWA draft for ik_llama

Sliding-window attention

Files

Use

Validation (RTX 4070, ik_llama DFlash SWA branch)

Conversion

ji-farthing/
Qwen3.5-35B-A3B-DFlash-SWA-ik-llama-GGUF