Two Ways to Shrink an AI Model. Only One Keeps the Output.

If your inference bill is climbing or you are running out of GPU memory, you have two ways to make a model smaller. Quantization cuts the most bytes but changes the model’s outputs, which is a problem for anything regulated or already validated. Lossless compression cuts about 30% of the bytes by re-packing the wasted space in BF16 weights, and the outputs come back bit-for-bit identical. The DFloat11 research confirms the 30% with zero accuracy change, and ZipNN reports similar. The 30% is a fixed ceiling, not a knob, so treat it as a free one-time discount for BF16 workloads that are memory-bound and cannot tolerate changed output. ISIRO Runtime is one commercial product built on this technique, with vendor-reported numbers worth testing rather than trusting. Before you quantize anything, run a bit-exact diff on a compiled model and measure whether your decode path is actually memory-bound.