OpenNMT / OpenNMT/CTranslate2

[feature request] Mixed quantizations.

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C++
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Description

From my own experience in text generation models, I found out that quantizing the output and embed tensors to f16 and the other tensors to q6_k (or q5_k) gives smaller files and better results that quantizing everything to q8_0.

Usually in my tests, i quantize the output and embed tensors to F16 and the inner ones to q5_k q6_k and q8_0.

The results I then test using llama.cpp qhich is quite fast even on cpu only...

Can you please add the feature to ctensor2 too?

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Research direction

The request targets mixed quantization in ctensor2 but names no files, tests, or implementation entry points. Start by locating ctensor2's quantization path and compare its behavior with the llama.cpp results described; done means supporting F16 output and embedding tensors alongside q5_k, q6_k, or q8_0 inner tensors with validated model results.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
machine-learning, performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

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