Rust-built PSSA beats a transformer by 0.45 nats and runs 12x faster on CPU
PSSA: A non-transformer language model written from scratch in Rust
PSSA is a non-transformer language model written from scratch in Rust, with no PyTorch or TensorFlow. It uses a recurrent state-space core, an episodic memory bank, and plastic weights. On 12.7M tokens of WikiText-103, a 1.5M-parameter PSSA reached 3.98 cross-entropy versus 4.43 for a matched transformer, and generated 200 tokens in 226 ms versus 2,735 ms on the same CPU.
The transformer spent its entire 12.7M-token budget to reach a loss PSSA had already passed around 2M tokens in.
- JPLeRouzic
I have read somewhere that Transformer architecture has a quadratic cost [0] (which explains the high costs associated with LLMs and the difficulty for constant improvement without state size pockets).
For what I understand PSSA belongs to a line of research for LLMs with scalable architecture because you don't need to load the full KV in memory to generate a single token:
[0] https://aclanthology.org/2023.findings-emnlp.936/
https://arxiv.org/abs/2503.00392
https://papers.nips.cc/paper_files/paper/2023/hash/6ceefa7b1...
- prospero_
Apparently none of the people complaining about rust use read past the title because it's the 2nd section of the readme and impossible to miss.
- janalsncm
OP, you should not have written this in Rust. It should be in PyTorch, which is by far the most popular. We can’t tell if this architecture is good or whether there is a problem in your implementation.
You can test the whole thing for free on a GPU with Google Colab. Test both the transformer and your new architecture on a larger dataset. Something that maxes out the GPU for an hour each run.
Also, the readme mentions keeping the same optimizer schedule which sounds nice at first but they are completely different architectures. The loss is high on the transformer, did you try raising the learning rate on it?
In general I’m interested in parameter efficient architectures. I don’t think transformers are optimal, and indeed many improvements have been made to vanilla transformers. But if you have an idea for something better you need to show it.
- mllev15
You can just tell when the idea itself was generated
- a19486
Homie just had some tokens to burn at the end of the month and “in Rust” is pure HN clickbait.