Quantization isn't (and wasn't) expensive, it's mostly just data shuffling. A good PC will do a 7B model in half a minute, up to a few minutes for a larger model. Quantized models being made available for download is more for the benefit of less technical users who may not be comfortable with the command-line tools, or for people with slow or metered connections who'd much rather download 15GB of data than download 60 only to squish it into 15.
This work introduces a new quantization scheme, NF4, for 4-bit NormalFloat, based on previous work on quantile quantization, so it's not a simple truncation, but it's also not a GPTQ-like optimization method. Figure 3 of the paper shows accuracy improvement of NF4 over FP4.
Comments
Quantization isn't (and wasn't) expensive, it's mostly just data shuffling. A good PC will do a 7B model in half a minute, up to a few minutes for a larger model. Quantized models being made available for download is more for the benefit of less technical users who may not be comfortable with the command-line tools, or for people with slow or metered connections who'd much rather download 15GB of data than download 60 only to squish it into 15.
The question is whether this step is actually doing the GPTQ optimized quantization, or simple truncation.
This work introduces a new quantization scheme, NF4, for 4-bit NormalFloat, based on previous work on quantile quantization, so it's not a simple truncation, but it's also not a GPTQ-like optimization method. Figure 3 of the paper shows accuracy improvement of NF4 over FP4.