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Even trillion parameters cannot save dirty data: domestic large-model developers have begun redoing pretraining

Dongcha Beating AI news flash: Leifeng.com reports that over the past months or more, multiple domestic large-model developers have begun redoing pretraining, with the problems all pointing to data.

One developer once spent nearly 1 years training a trillion-parameter model, but its actual performance was surpassed by a small model with only about 1%parameters. The team eventually discovered that the problem lay in the training data. Web junk, duplicate corpora, and low-quality annotations had entered the training set; no matter how large the model, it could not handle them. This case came from an anonymous source, and the specific company has not been disclosed.

Tencent Hunyuan has publicly disclosed that it redid one round. Starting this year,February the team rebuilt its pretraining and reinforcement-learning infrastructure. Media reports had previously revealed problems in the old Hunyuan, including benchmark data entering the training set and chaotic annotation rules. The new team reset the data standards and cleaned the original corpora, while Hy3 also listed data quality and diversity as major areas for improvement.

Alibaba and Baidu are also stepping up data governance. Qwen3 used the Qwen2.5 series models to clean documents and added large amounts of synthetic mathematics and code data. Wenxin 4.5 then added deduplication, low-quality filtering, a data map, and human review. Neither company has publicly said that it had previously reworked its models because of dirty data, but the new-generation models are both devoting more effort to data processing.

Original link https://m.theblockbeats.info/flash/368576