SAW rotation wins KV cache sweep

The takeaway is pretty blunt: if you want KV compression that actually survives contact with real models, SAW looks like the safest default, not TurboQuant-style 3-bit heroics.

• –On Llama 3.1 8B, `saw4k` roughly halves the quality hit versus `q4k` at similar KV savings, which is the kind of delta that matters in production
• –`saw8k` and `saw8kv` are close to lossless across several models, so 8-bit SAW looks like the low-risk choice when memory pressure is moderate
• –Qwen2.5 7B exposes a hard failure mode for 4-bit KV quantization because its K projection bias makes int4 noise swamp the signal
• –Gemma 4 shows that architecture matters more than slogans: some presets OOM or produce garbage PPL, so these methods are not universally portable
• –The benchmark makes a strong case for treating KV quantization as model-specific systems work, not a one-size-fits-all compression trick