A controlled study evaluates OpenPangu 1B and 7B models on Huawei Ascend 910B1 NPUs using weight-only and weight-activation quantization methods. Results show 8-bit weight-only quantization is lossless for both models, while 4-bit quantization is practical for 7B but harmful for 1B on reasoning, math, and code tasks. Ultra-low precision methods like 2-bit and binary fail, and W4A4 SmoothQuant produces non-finite perplexity, indicating extreme low-bit compression remains challenging.