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A generic block diagram of a GPU.

Radeon DNA (RDNA)[1][2] is the codename for a GPU microarchitecture and accompanying instruction set developed by AMD for their GPUs as the successor to their GCN microarchitecture/instruction set. The first product lineup featuring RDNA will be the Radeon RX 5000 series of video cards slated to launch in July 2019.[3] The architecture is also planned to be used in mobile products and the upcoming next generation of game consoles by Sony and Microsoft.[4]

It is likely to be RISC SIMD (or rather SIMT) microarchitecture.[citation needed] It is going to be manufactured and fabricated with TSMC's 7 nm FinFET graphics chips used in the Navi series of AMD Radeon graphics cards.[5]

Contents

ArchitectureEdit

The architecture features a new processor design, although the first details released at AMD's Computex keynote hints at aspects from the previous a Graphics Core Next (GCN) architecture being present. It will feature multi-level cache hierarchy and an improved rendering pipeline, with support for GDDR6 memory. A completely redesigned (non-hybrid) architecture is planned as a successor (rumor).[6]

Starting with the architecture itself, one of the biggest changes for RDNA is the width of a wavefront, the fundamental group of work. GCN in all of its iterations was 64 threads wide, meaning 64 threads were bundled together into a single wavefront for execution. RDNA drops this to a native 32 threads wide. At the same time, AMD has expanded the width of their SIMDs from 16 slots to 32 (aka SIMD32), meaning the size of a wavefront now matches the SIMD size.[7]

RDNA also introduces working primitive shaders. While the feature was present in the hardware of the Vega architecture, it was difficult to get a real-world performance boost from and thus AMD never enabled it. Primitive shaders in RDNA are compiler-controlled.[7]

The display controller in RDNA has been updated to support Display Stream Compression 1.2a, allowing output in 4k@240 Hz, HDR 4K@120 Hz, and HDR 8K@60 Hz.[7][8]

PerformanceEdit

AMD claims a 1.25x increase in performance per clock and a 1.5x increase in performance per watt over the GCN architecture used in the last Vega series of GPUs.[6]

Instruction setEdit

The RDNA instruction set is owned by AMD (that also owns the X86-64 instruction set).

ReferencesEdit

  1. ^ Smith, Ryan (26 May 2019). "Home> GPUs AMD Teases First Navi GPU Products: RX 5700 Series Launches in July, 25% Improved Perf-Per-Clock". AnandTech. Retrieved 21 June 2019.
  2. ^ "AMD RDNA Architecture".
  3. ^ AMD launches RX 5700 XT and RX 5700 GPUs with RDNA architecture
  4. ^ Smith, Ryan (10 June 2019). "GPUs AMD Announces Radeon RX 5700 XT & RX 5700: The Next Gen of AMD Video Cards Starts on July 7th At $449/$379". AnandTech. p. 1. Retrieved 21 June 2019.
  5. ^ "AMD Radeon RX 5700 XT release date, price, specs, and performance". PCGamesN. Retrieved 28 June 2019.
  6. ^ a b "AMD Radeon RX 5000 With Navi GPUs A Hybrid of RDNA & GCN Chip Architecture – Pure RDNA Based 'Navi 20' GPU Coming in 2020".
  7. ^ a b c Smith, Ryan (10 June 2019). "GPUs AMD Announces Radeon RX 5700 XT & RX 5700: The Next Gen of AMD Video Cards Starts on July 7th At $449/$379". AnandTech. p. 2. Retrieved 21 June 2019.
  8. ^ Stobing, Chris (10 June 2019). "AMD Details Radeon RX 5700 'Navi' GPUs: Here's What You Need to Know". PC Magazine. Ziff Davis, LLC. Retrieved 21 June 2019.