WMT26 Model Compression Task: Quantising and Distilling TildeOpen

Martins Kronis, Toms Bergmanis, Ingus Pretkalniņš, Marcis Pinnis


Abstract
This paper describes Tilde’s submission to the unconstrained track of the WMT~2026 Model Compression task in the Czech-German direction. Our baseline is TildeOpen-15B-64k, a model distilled from the TildeOpen-30B-64k European foundation model. We adapt it for CS-DE translation, using supervised fine-tuning followed by GRPO-based reinforcement learning. From this baseline, we explore two axes of compression: post-training quantisation and knowledge distillation. For quantisation, we use LLM Compressor to produce a GPTQ-calibrated model with 4-bit NVFP4 weights (10.1\,GB, $\times$3 smaller than the 30.3\,GB footprint of the 15B baseline) and a data-free RTN model with FP8 weights and activations (16.3\,GB). In parallel, we prune and distil the base 15B model into an 8B student and fine-tune it with the same supervised fine-tuning recipe. Applying the two quantisation schemes to the 8B model yields our smallest models at 8.9\,GB and 5.7\,GB. The latter is over $\times$5 more compact and $\times$1.8 faster than the 15B baseline. Evaluation on four test sets across a variety of metrics shows that quantisation and distillation have minimal impact on translation quality. The NVFP4-quantised 15B model offers the best quality/size/speed trade-off and is our primary submission for this competition. All six models are publicly released.
Anthology ID:
2026.wmt-main.137
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1999–2008
Language:
URL:
https://aclanthology.org/2026.wmt-main.137/
DOI:
Bibkey:
Cite (ACL):
Martins Kronis, Toms Bergmanis, Ingus Pretkalniņš, and Marcis Pinnis. 2026. WMT26 Model Compression Task: Quantising and Distilling TildeOpen. In Proceedings of the Eleventh Conference on Machine Translation, pages 1999–2008, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
WMT26 Model Compression Task: Quantising and Distilling TildeOpen (Kronis et al., WMT 2026)
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PDF:
https://aclanthology.org/2026.wmt-main.137.pdf