AMD RDNA 3 ‘GFX11’ GPU Patches Enable VCN4 Support But Lack AV1 Encoding
AMD commenced the release of patches for its RDNA 3 (GFX11) architecture last week, contributing to the LLVM project. The latest GFX11 architecture underpins the Navi 3X GPU series, built upon the RDNA 3 framework. With the recent activation of this support, AMD’s software engineers have embarked on developing functionality tailored to this architecture, slated for release later this year. Notably, the inclusion of VCN 4.0 (Video Core Next IP block) facilitates video codec information storage. However, AMD has yet to enable AV1 encoding, a feature introduced by Intel for enhanced efficiency over AVC encoding.
AMD initiates VCN 4.0 enablement for RDNA3-based ‘GFX11’ GPUs but omits AV1 encoding support for now.
In addition to the absence of Intel’s new encoding in AMD’s support, there has been a renaming of VCN 4.0 since the last update. Previously known as ‘Video Core Next,’ it is now labeled ‘Video Codec Next.’ The rationale behind this alteration by AMD’s software engineers remains undisclosed, raising questions of intent or potential error in publishing. Nonetheless, the inclusion of ‘codec’ suggests a broader capacity for representation than the prior nomenclature.
Regarding the recent VCN 4.0 patch, Michael Larabel of Phoronix reports an addition of over twelve thousand lines of new code, predominantly comprising register header files. As VCN4 enablement unfolds, it’s premature to draw definitive conclusions or implications for the future.
The SOC21 (Navi 31) GPU code encompasses AVC, HEVC encoding, AVC, HEVC, JPEG, VP9, and AV1 decoding capabilities. While these encoding and decoding capabilities constitute the initial roster of supported codecs, the absence of AV1 encoding poses a significant gap for RDNA3 GPUs. Presently, Intel Xe-HPG architecture is the sole provider of AV1 encoding support. As Intel Arc GPUs enter the market, the open-source AV1 standard is poised to gain momentum.
AMD’s RDNA3 graphics cards are slated for release in the fourth quarter of 2022, anticipated to rival NVIDIA’s GeForce RTX 40 series. As the fourth quarter approaches, further revisions to the VCN4 code are expected, potentially expanding the roster of supported codecs by AMD.
Source: Freedesktop, Phoronix, Kepler (@Kepler_L2 on Twitter)
