- in
- [B batch, T positions, 768 d]
- out
- [B batch, T positions, 768 d]
- parameters
- 55,098,650
- mode
- generation
Parameters
55,098,650 parameters per instance, across its learned components
| Component | Calculation | Parameters |
|---|---|---|
| Position table | 786,432 | |
| Mask vector | 768 | |
| Query MLP | 4,723,968 across its components | 4,723,968 |
| Residual scale | 2 | |
| Decoder block | 49,587,480 | |
| Per-instance total | 55,098,650 | |
Derived from the pinned implementation’s constructors and configuration. The checkpoint’s tensors have not been counted. 306,011,162 of these parameters are trained; frozen GPT-2 and the decoder’s mask vector, 124,442,112, are not.
Explanation
Every position starts from the same vector, the frozen embedding of <mask>; positions tell them apart, and everything else they read from the latents.
There is no normalization after the last block: the output is compared with the standardized features as it is.
Sources4
Direct evidence
The latent decoder owns one position table, the mask token’s vector copied from the token table of a GPT-2 loaded for the purpose and frozen because the feature model is configured frozen, an MLP for the queries, the blocks and a scale for the prepared queries.
The implementation, pinned at revision e18c42acdfb7, not yet public
Direct evidence
Every query is the mask vector: it passes the MLP and a scale, positions are added; the latents take the same position table; the blocks are applied; every position counts as masked.
The implementation, pinned at revision e18c42acdfb7, not yet public
Direct evidence
The latent decoder: 12 heads of 64 features, query and key normalization, softcap 50, 6 layers, MLP multiplier 4; the token decoder has 3 blocks.
The implementation, pinned at revision e18c42acdfb7, not yet public
Direct evidence
The feature model is GPT-2, frozen; the hidden state at index −3 is extracted; the encoder and the decoder are of the Perceiver kind; the file’s vocabulary size and mask token ID are defaults that the trainer overwrites with the tokenizer’s; there are as many latents as positions, of 768 features.
The implementation, pinned at revision e18c42acdfb7, not yet public