Available quantisations are confusing

#2
by jpeg729 - opened

HuggingFace lists four available quants

  • 1-bit = 4.98Gb
  • 2-bit = 5.9Gb
  • 16-bit = 5.43Gb and/or 6.35Gb
    How the hell is a 16 bit quant smaller than a 2-bit quant?

If you look at the file listings you see

  • maple-preview-TQ1_0-head-F16.gguf = 5.43Gb
  • maple-preview-TQ1_0-head-Q4_K.gguf = 4.89Gb
  • maple-preview-TQ2_0-head-F16.gguf = 6.53Gb
  • maple-preview-TQ2_0-head-Q4_K.gguf = 5.9Gb
    Why does a TQ2 masquerade as F16 and Q4_K?

When I use the huggingface "Use this model option" it proposes llama cli -hf deepgrove/maple-preview-GGUF:F16
If I switch to TQ1_0 it downloads the maple-preview-TQ1_0-head-F16.gguf file.
If I manually type llama cli -hf deepgrove/maple-preview-GGUF:TQ1_0-head-Q4_K I can make it download the Q4_K file which is smaller, for no apparent reason.

Can someone explain the differences?

deepgrove org

The confusion comes from the precision of the lm-head.

Decoder layers in our model are in ternary precision - which can be represented with tq1 and tq2 (different packing methods trading off memory for speed).

The separate precision of either q4 or f16 is the precision that the lm-head runs on.

Please refer to https://github.com/deepgrove-ai/llama.cpp for more details.

deepgrove-team changed discussion status to closed

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