Computing power
Training Apertus took more than 10 million GPU hours on Alps, the supercomputer of the Swiss National Supercomputing Centre (CSCS). A GPU hour is one graphics processor working for one hour.
The scale is new, but the problem is old: in the 1950s ETH Zurich built ERMETH because it needed more computing power than it could get any other way.
Data
Apertus learned from 15 trillion tokens, the small pieces of words that language models work with, in more than 1,000 languages. Because the training data were published, researchers can study what went into the model, which matters for questions of quality, bias and copyright.
Sources
- ETH Zurich, Apertus: a fully open, transparent, multilingual language model (press release)
- ETH Zurich, Department of Computer Science: Development of the department
Sources checked on: 1 November 2026
