Microsoft Unveils BitNet: A Hyper-Efficient AI Model for CPUs

Microsoft researchers have introduced BitNet b1.58 2B4T, a hyper-efficient AI model designed to run on CPUs, including Apple's M2. This model, described as the largest-scale 1-bit AI model or 'bitnet' to date, is openly available under an MIT license. Bitnets are compressed models that quantize weights into three values: -1, 0, and 1, making them more memory- and computing-efficient than traditional models.

BitNet b1.58 2B4T, with 2 billion parameters, was trained on a dataset of 4 trillion tokens. It reportedly outperforms traditional models of similar sizes, such as Meta's Llama 3.2 1B and Google's Gemma 3 1B, on benchmarks like GSM8K and PIQA. The model is also noted for its speed, operating at twice the speed of other models of its size while using significantly less memory.

However, to achieve optimal performance, BitNet requires Microsoft's custom framework, bitnet.cpp, which currently supports only certain hardware, excluding GPUs. This limitation highlights a potential challenge in broader adoption, as GPUs are prevalent in AI infrastructure.