𝐃𝐞𝐥𝐭𝐚 𝐀𝐭𝐭𝐞𝐧𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐢𝐝𝐮𝐚𝐥𝐬 [R]

We're excited to release 𝐃𝐞𝐥𝐭𝐚 𝐀𝐭𝐭𝐞𝐧𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐢𝐝𝐮𝐚𝐥𝐬, a drop-in upgrade to residual connections that learns which past layers to route from — without the routing collapse that breaks prior cross-layer attention at scale. 🚀

Attention Residuals route over cumulative hidden states, but those are highly redundant, so routing collapses to near-uniform (max weight ~0.2) in deep layers. Delta Attention Residuals route over 𝐝𝐞𝐥𝐭𝐚𝐬 (vᵢ = hᵢ₊₁ − hᵢ) — what each sublayer actually contributed — and natively enable:

⚡ 𝟏.𝟖× 𝐬𝐡𝐚𝐫𝐩𝐞𝐫 𝐜𝐫𝐨𝐬𝐬-𝐥𝐚𝐲𝐞𝐫 𝐫𝐨𝐮𝐭𝐢𝐧𝐠 Deltas are structurally diverse, lifting max attention weight from ~0.2 → ~0.6 (0.62 vs 0.35 avg) and curing routing collapse in deep layers.

📉 −𝟖.𝟐% 𝐯𝐚𝐥𝐢𝐝𝐚𝐭𝐢𝐨𝐧 𝐏𝐏𝐋 𝐚𝐭 𝟕.𝟔𝐁 Consistent gains from 220M → 7.6B (1.7–8.2% lower PPL), beating both standard residuals and Attention Residuals — the latter actually degrades below baseline at scale (18.58 vs 17.43).

🔌 𝐃𝐫𝐨𝐩-𝐢𝐧 𝐟𝐢𝐧𝐞-𝐭𝐮𝐧𝐢𝐧𝐠 𝐨𝐟 𝐩𝐫𝐞𝐭𝐫𝐚𝐢𝐧𝐞𝐝 𝐦𝐨𝐝𝐞𝐥𝐬 Additive, zero-init routing is identity at initialization, so you can convert pretrained checkpoints (e.g. Qwen3-0.6B) into Delta Attention Residuals via standard fine-tuning — beating the original on 8 downstream benchmarks (55.6 vs 55.0).

🪶 ≤𝟎.𝟎𝟏% 𝐩𝐚𝐫𝐚𝐦𝐞𝐭𝐞𝐫 𝐨𝐯𝐞𝐫𝐡𝐞𝐚𝐝 Delta Block adds just 589K params (0.008% at 8B) and ~3% memory — and runs faster + lighter than Attention Residuals (14.0k vs 12.5k tok/s, 42.7 vs 44.0 GB).

💻 Code: https://github.com/wdlctc/delta-attention-residuals-code

💻 Paper: https://arxiv.org/abs/2605.18855

https://preview.redd.it/bewovgw25b3h1.png?width=1359&format=png&auto=webp&s=6cee758f7a96f0adecd9a3fb8553dde3f1b92c74