Xiaomi Xuanjie O3 chip supports BCn texture formats, aiding PC game compatibility

NotebookCheck reported that Xiaomi's in-house Xuanjie O3 chip supports the BCn block-compressed texture format family (BC1 to BC7), based on Vulkan feature report data. This could help pave the way for PC game compatibility on mobile devices.

The Xiaomi 18 Fold (model 2608BPX34C) supports sampling, bitmap transfer and data transfer for all BC1 to BC7 subtypes. Since the Xiaomi Pad 9 Pro Max also uses the Xuanjie O3 chip, the publication expects it to support BCn as well.

BCn is a group of block-compressed texture formats widely used on PCs and game consoles. Android native systems typically rely on ASTC and ETC2. The formats compress texture data into fixed 4×4 pixel blocks, allowing GPUs to decode blocks on demand rather than decompressing entire files, which can save VRAM, memory bandwidth and power.

NotebookCheck noted that BCn support is rare among current Arm Mali GPU IP, and MediaTek Dimensity and Google Tensor chips do not support it. In everyday phone use, apps rarely depend on BCn, so there is little noticeable difference. The main benefit comes when running Windows games on phones through compatibility layers like Winlator or Proton, where BCn support could reduce reliance on CPU-side texture decompression and potentially lower memory usage, power consumption and stuttering.