Architecture

AMD Radeon RX 7600 is based on the Navi 33 silicon that the company chose to build on the older 6 nm (DUV) foundry node that significantly lowers transistor density than the 5 nm EUV node that the Navi 31 powering the RX 7900 series is based on. The chip has a die-area of 204 mm², and transistor count of 13.3 billion (for reference, NVIDIA is able to cram 22.9 billion transistors into a 190 mm² silicon using 5 nm, with the AD106 powering the RTX 4060 Ti). The GPU has essentially the same component hierarchy as the previous-generation Navi 23. Its host interface is PCI-Express 4.0 x8, and power is drawn from a single 8-pin PCIe power connector, which is sufficient, given the gaming total board power for the RX 7600 of 169 W. The GPU features a 128-bit wide GDDR6 memory interface, and 8 GB is the VRAM size for the RX 7600.

AMD hasn't put out a block diagram of the Navi 33, but it features two Shader Engines (compared to six on the Navi 31). Each of these has 8 RDNA 3 Dual-Compute Units (16 CU), which share Raster machinery, and Render Backends. The GPU features Centralized Geometry Processors, asynchronous compute engines, and geometry processors shared among the two Shader Engines. Given its CU count of 32, we arrive at 2,048 stream processors, 32 Ray Accelerators, 64 AI Accelerators, 128 TMUs, and 64 ROPs. The GPU uses a 2nd Gen 32 MB Infinity Cache memory that cushions data access to the memory.


Much of the architectural innovation is this generation is with the RDNA 3 Dual-Compute Unit (or Compute Unit pair). The "Navi 33" GPU physically features 32 compute units spread across two Shader Engines. AMD claims that at the same engine clocks, the RDNA 3 CU offers a 17.4% IPC increase over the RDNA2 CU.


The new RDNA 3 CU introduces multi-precision capability for the 64 stream processors per CU: operating either as 1x SIMD64 or 2x SIMD32 units. The Vector Unit that houses these SIMD units can either function as a SIMD execution mechanism, or as a Matrix execution unit, thanks to the new AI Matrix Accelerator, which provides a 2.7x matrix multiplication performance uplift versus conventional SIMD execution. Also added are support for the Bfloat16 instruction-set, and SIMD8 execution. The GPU hence enjoys AI hardware-acceleration that can be leveraged in future feature-additions relevant to gamers, such as FSR 3.0. Game developers will also look for ways to exploit accelerated AI, now that all three brands feature it (NVIDIA Tensor cores and Intel XMX cores).


AMD's first-generation Ray Accelerator, introduced with the RDNA2 architecture, was the result of a hasty effort to catch up to NVIDIA with a DirectX 12 Ultimate GPU, where they developed a fixed-function hardware to calculate ray intersections, and offloaded a large chunk of RT processing to the generationally-doubled SIMD resources. With RDNA 3, they've refined the Ray Accelerator to achieve an 80% ray tracing performance uplift over the previous generation, when you add up the Ray Accelerator count, their higher engine clocks, and other hardware-level optimizations, such as early sub-tree culling, specialized box sorting modes, and reduced traversal iterations.


There is a 50% ray intersection capacity improvement for RDNA 3 thanks to these optimizations, and cycles-per-ray reduction. Besides these, AMD has also made several improvements to the geometry- and pixel-pipes, with the introduction of the new multi-draw indirect accelerator (MDIA), which reduces CPU API and driver-level overheads by gathering and parsing of multi-draw command data. At the hardware-level 12 primitives per clock is now supported compared to 8 per clock on RDNA2, thanks to culling. The core-configuration overall enables 50% more rasterized performance per clock.


AMD has significantly improved the Display Engine of "Navi 33" over the previous-generation in terms of connectivity. The new Radiance Display Engine comes with native support for DisplayPort 2.1, which enables 8K output at up to 165 Hz refresh-rate, or 4K at up to 480 Hz, with a single cable. AMD has refined its FSR 2 algorithm to support 8K (i.e. render at a lower resolution with FSR-enhanced upscaling), to make it possible to enjoy the latest AAA titles at playable frame-rates on 8K displays. The RX 7600 gets two full-size DP 2.1 connectors, besides an HDMI 2.1b, and a USB-C with DP 1.2 passthrough. The "Navi 33" silicon receives full hardware-accelerated AV1 encode and decode capabilities. With this generation, AMD is also introducing SmartAccess Video, a feature that lets the AMD driver leverage the hardware encoders of the RDNA2 iGPU of Ryzen 7000 desktop processors, for additional encoding performance.