There's two variants of this (or, as the joke goes, for very big values of bit):
Ternary Bonsai 27B uses ternary {−1, 0, +1} weights with FP16 group-wise scaling, giving a true 1.71 effective bits per weight.
1-bit Bonsai 27B uses binary {−1, +1} weights with the same group-wise scaling, giving 1.125 effective bits per weight.
this is a really dumb question, but how is -1 represented?
is it a float? if so, how many bits is the float?
I've never heard of a bit ever having more than two possible values