PEFT (Parameter-Efficient Fine-Tuning)

Fine-tune LLMs by training <1% of parameters using LoRA, QLoRA, and 25+ adapter methods.

When to use PEFT

Use PEFT/LoRA when:

• Fine-tuning 7B-70B models on consumer GPUs (RTX 4090, A100)
• Need to train <1% parameters (6MB adapters vs 14GB full model)
• Want fast iteration with multiple task-specific adapters
• Deploying multiple fine-tuned variants from one base model

Use QLoRA (PEFT + quantization) when:

• Fine-tuning 70B models on single 24GB GPU
• Memory is the primary constraint
• Can accept ~5% quality trade-off vs full fine-tuning

Use full fine-tuning instead when:

• Training small models (<1B parameters)