They are int4 quantized

Does int4 mean 4 bits per integer, or 4 bytes/32-bits.

If it means that weights for an LLM can be 4 bits well that's just mind boggling.

Four bits per parameter. (A parameter is what you call an integer here.)

I was skeptical of it for some time, but it seems to work because individual parameters don’t encode much information. The knowledge is embedded thanks to having a massive number of low bit parameters.

4 bits