- Fold the family into the main Variants table as rows (CorDA/ablate/arrow) instead of a separate table. - Lead with the point (freeze W's SVD, learn only a bounded gain -> interpretable, O(r) params) before any numbers. - Replace the unsourced 'PEFT reports 49.0%' line (wrong; LoRA is ~48%) with a real link to PEFT's method_comparison/MetaMathQA and a pointer to the benchmark script for hyperparameters. Link CorDA/Arditi papers inline. Co-Authored-By: Claudypoo <noreply@anthropic.com>
3.9 KiB
lora-lite
Hackable PyTorch adapters for LoRA-family and small PEFT experiments.
Hackable code
To keep it simple and hackable we make these choices:
- Simple forward hooks, no module replacement or custom modules.
- Simple code over fast performance
- No merge/unmerge
- Single test where we train on MetaMathQA and test on GSM8K for each variant
Take a look at lora.py
Install
pip install -e git+https://github.com/wassname/lora-lite.git#egg=lora-lite
Quickstart
import torch, lora_lite as ll
model = MyTransformer()
cfg = ll.LoRAConfig(r=8, alpha=16, dtype=torch.bfloat16)
ll.attach(model, cfg)
opt = torch.optim.AdamW([p for p in model.parameters() if p.requires_grad], lr=1e-4)
# train...
ll.save(model, "adapter.safetensors")
ll.detach(model)
ll.load(model, "adapter.safetensors")
Does it work?
just check # pytest + smoke + package build + metadata check
just bnb-smoke # required CUDA bitsandbytes 4bit/8bit smoke
just qwen-probe # Qwen/Qwen3-0.6B train/save-load probe
Variants
| Variant | 4bit/8bit | GSM8K % | Params | Peak GPU (GB) |
|---|---|---|---|---|
| LoRA | yes | 63.2% | 4.59M | 11.3 |
| PiSSA | no | 63.2% | 4.59M | 11.3 |
| DoRA | no | 62.4% | 4.67M | 11.3 |
| DeLoRA | yes | 61.5% | 4.59M | 11.3 |
| AntiPaSTO | no | 61.4% | 14.3K | 11.3 |
| AntiPaSTO-CorDA | no | 61.9% | 14.3K | 11.3 |
| AntiPaSTO-ablate | no | 61.0% | 14.4K | 11.3 |
| AntiPaSTO-arrow | no | 60.5% | 17.5K | 11.3 |
| IA3-FF | yes | 61.4% | 86K | 11.4 |
| EVA | no | 60.3% | 4.59M | 11.3 |
| IA3 | yes | 60.0% | 57K | 11.4 |
| HRA | yes | 61.6% | 1.84M | 11.3 |
Params = trainable adapter params. Peak GPU = peak CUDA memory during train+eval (logged from this run onward; older runs predate the column).
Setup follows PEFT's method comparison: train on a MetaMathQA subset, test on GSM8K. We swap their Llama-3.2-3B (where LoRA gets ~48%) for the smaller Qwen3-0.6B-Base, so these track method rank, not cross-setup absolutes. Hyperparameters are in the benchmark script (r=32 q/v; the AntiPaSTO family uses r=256).
AntiPaSTO is the novel row here: instead of adding trainable directions like LoRA, it freezes W's own top-r SVD and learns only a bounded per-direction gain S_eff = S * (1 + ELU(g)). The singular basis stays fixed and interpretable, and the adapter is O(r) params (~320x smaller than LoRA). The variants change only the basis or core: CorDA orients it by input covariance (Yang+ 2024), ablate learns a contractive directional ablation (Arditi+ 2024), arrow adds a small dense block for cross-direction mixing.
Developer docs
See docs/developer_guide.md for the variant API, data-calibrated init, and save/load format.
Citation
@misc{wassname2026loralite,
title = {LoRA-Lite: A Hackable Adapter Library for Research},
author = {Michael J. Clark},
year = {2026},
url = {https://github.com/wassname/lora-lite/}
}