Radeon RX 6400

AMD Radeon RX 6400 Graphics Cards

The AMD Radeon RX 6400 was introduced in early January 2022. With this graphics card based on the RDNA2 GPU architecture (Navi II), AMD is expanding its product portfolio in the entry-level segment. The Navi 24 XL graphics chip used is manufactured with a 6 nm process, has 768 shader units and 4 GB VRAM, and is thus designed for gaming in Full HD resolution. In addition to hardware-accelerated ray tracing and AMD's Infinity Cache of the RX-6000 series, the AMD Radeon RX 6400 offers various gaming technologies such as FidelityFX or AMD FreeSync.

Performance Data of the Radeon RX 6400 Graphics Card (Reference Design):

• Compute Performance (FP32): approx. 3.57 TFLOPS
• GPU Base Clock: 1,923 MHz
• GPU Game Clock: 2,039 MHz
• GPU Boost Clock: 2,321 MHz
• Graphics Memory: 4 GB GDDR6
• Memory Clock: 2,000 MHz (effective 16,000 Mbps)
• Memory Interface: 64 Bit
• Memory Bandwidth: 128 GB/s
• Shader Units: 768
• TDP of 53 Watts
• Power Supply: via PCIe Interface
• Video Outputs: DP 1.4, HDMI 2.1

Radeon RX 6400: The RDNA2 GPU Architecture

The AMD Radeon RX 6400 is based on the Navi 24 XL graphics chip, which consists of 5.4 billion transistors. The total of 768 stream processors (shader units) are divided into groups of 64 shaders on 12 compute units (CUs, computational units). In addition to the 12 shaders, each CU is assigned a "Ray Accelerator" for hardware-based ray tracing.

The GPU clocks on average in games with a game clock of up to 2,039 MHz. In particularly high-demand situations, the graphics chip can boost up to 2,321 MHz. The RDNA2 compute units clock up to 30 percent higher at the same power loss as the predecessor. And in terms of energy efficiency, Big Navi delivers about 65% more performance per watt compared to the first Navi generation. The AMD Infinity Cache also plays a role here.

Infinity Cache & Video Memory

Among the new features of the RDNA2 architecture is AMD's Infinity Cache. The AMD Infinity Cache enables an effective memory bandwidth increase by a factor of 3.25. With a normal 64-bit memory interface and a memory clock of 2,000 MHz, this results in a memory bandwidth of 128 GB/s.

For video memory (VRAM), AMD uses the GDDR6 standard with a capacity of 4 GB in the Navi II graphics cards. Thanks to the mentioned Infinity Cache, this effectively achieves a performance equivalent to faster GDDR6X. Thus, AMD can implement a powerful combination of high speed and high capacity on the graphics card without resorting to the more expensive memory type.

Smart Access Memory

With the Smart Access Memory (SAM) technology, AMD promises additional performance when combining a Radeon RX 6400 graphics card with a Ryzen 5000 processor on a motherboard with a B550 or X570 chipset. SAM uses the resizable BAR function of the PCIe standard. A corresponding gaming system is expected to benefit from a minimal performance increase. The extent of the performance gain depends on the game and the selected resolution.

Additional Features

The many smaller optimizations of the RDNA2 GPU architecture include:

• HDMI 2.1 for 4K monitors with 120 Hz
• Variable Rate Shading (DirectX 12 Ultimate)
• Mesh Shader (DirectX 12 Ultimate)
• Sampler Feedback (DirectX 12 Ultimate)
• 4K-H264 & H.256/HEVC decoding

Ray Tracing & FidelityFX

With the Ray Accelerators, AMD offers hardware-based ray tracing. Ray tracing (Microsoft DirectX 12 DXR) enables realistic lighting through the simulation of physical properties and the behavior of light. Ray tracing calculates the color of individual pixels based on the path that light takes from the user's eye through a 3D landscape.

On its way through the 3D scene, light is reflected by objects or generates reflections. At the same time, shadows, transparent, or semi-transparent objects are created, resulting in light refractions or distortions. All these effects are combined by ray tracing to represent the final color of a pixel on the monitor.

As a relatively new technology, ray tracing places very high demands on hardware. With FidelityFX, AMD implements a super-resolution technology to relieve the ray tracing accelerators.

Gaming Technologies

Together with the hardware in the form of graphics cards, AMD introduces new gaming technologies to provide PC gamers with a better experience. Supported features for gamers include:

• Performance presets in the Radeon Adrenalin software
• AMD Radeon Anti-Lag
• AMD Radeon Boost
• AMD FreeSync (4K@240Hz, 8K@60Hz)
• Supports HDMI 2.1 VRR

The Current AMD RX 6000 Graphics Cards at a Glance:

Do you want to know which AMD graphics card is right for you? The following list includes all current models of the RDNA-2 generation, sorted by performance, starting with the most powerful graphics card.

• AMD Radeon RX 6950 XT
• AMD Radeon RX 6900 XT
• AMD Radeon RX 6800 XT
• AMD Radeon RX 6800
• AMD Radeon RX 6750 XT
• AMD Radeon RX 6700 XT
• AMD Radeon RX 6700
• AMD Radeon RX 6650 XT
• AMD Radeon RX 6600 XT
• AMD Radeon RX 6600
• AMD Radeon RX 6500 XT
• AMD Radeon RX 6400