Texture Compression using ASTC

Why use ASTC?

For latest legacy Rogue and all Volcanic cores, Imagination GPUs offers compatibility with ASTC (Adaptive Scalable Texture Compression) for the best performance and quality.

ASTC is one of the most flexible and efficient texture compression formats available. It supports a wide range of block sizes—from 4x4 (high quality) to 12x12 (high compression)—allowing developers to choose the right balance between image quality and memory footprint. This scalability makes ASTC suitable for nearly every texture in an application. It supports both HDR and LDR content and is available on most modern GPUs, including the latest PowerVR Graphics Cores.

Performance improvement on ASTC

The scalability of ASTC means developers can precisely tailor the texture resolution and compression level to the needs of their application. Smaller block sizes provide better image quality, while larger block sizes significantly reduce memory usage and bandwidth. In memory-constrained environments, ASTC can enable substantial performance gains by minimizing texture memory transfers and improving cache utilization. This fine-grained control often translates to smoother performance and better resource allocation.

Power consumption on ASTC

Reducing memory bandwidth requirements directly impacts power efficiency—especially critical in mobile and embedded platforms. ASTC helps lower power consumption by reducing the frequency and size of memory accesses. Its support for fine-tuned compression also allows developers to optimize texture usage more precisely, avoiding unnecessary power draw while maintaining visual quality.

This allows all the advantages mentioned above, but puts some limits on the form the compression technique may take. To allow for direct use by the graphics accelerator, a texture format should be optimised for random access, with a minimal size of data from which to retrieve each texel’s values. Consequently, texture compression schemes are usually fixed bitrate with very high data locality. Image file formats are not constrained by these requirements, and can often achieve higher compression ratios and image quality for a given data size.