Phi vs. Pythia

Phi

Phi is Microsoft's family of compact open models designed for efficient local and edge deployment. Phi-4 is the current generation.

Microsoft introduced Phi-1 and Phi-2 to demonstrate how carefully curated and synthetic training data can make small models unusually capable. Phi-3 expanded the family for mobile and multimodal use. The Phi-4 generation includes a 14B general model and reasoning variants, plus smaller and multimodal checkpoints. Phi models are released under the MIT license and are designed for research, local inference, and resource-constrained production workloads.

Further reading

• huggingface.co/microsoft/phi-2
• arxiv.org/abs/2306.11644
• huggingface.co/microsoft/phi-4

Pythia

The most recent (as of May 2023) effort from EleutherAI, Pythia is a set of LLMs trained on The Pile. While it appears to outperform OPT and GPTNeo, its performance against GPT-J is unclear. Versions of Pythia have also been instruct-tuned by the team at Together.