It is very expensive to train these base models so a smaller size is more practical if you aren’t a big company with hundreds of powerful GPUs at hand. Table 15 from LLaMA paper[1] has some insightful figures: it took 135,168 GPU hours to train the 13B version and a bit more than 1M GPU hours for the 65B version. And we are talking about A100 80GB GPUs here (expensive and scarce). Not everyone can afford these kinds of trainings (especially if it takes a few attempts; e.g. if you’ve got a bug in the tokenizer)