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AMD’s Radeon 6700 XT is surprising

17 billion transistors and AMD's new Ray Accelerator Technology

Posted: By Jon Peddie & Robert Dow 03.17.21

AMD is putting out some very impressive gaming AIBs that may be overlooked by gamers in general. These boards are giving mainstream gamers impressive performance at the midrange price point. 

AMD’s reference design Radeon 6700 XT AIB

The Radeon RX 6700 XT supports the latest graphical software suites such as DirectX 12 Ultimate and AMD’s FidelityFX5 feature set. Fidelity FX5, says AMD, brings realistic lighting, shadows, and reflections detail. Via DirectX' Raytracing (DXR), as well as variable-rate shading (VRS). And AMD adds FidelityFX features5 are optimized for AMD RDNA 2 architecture to power the next generation of gaming visuals at high framerates.

Other features such as Radeon Anti-Lag, which AMD says is supported in thousands of games running on Microsoft's DirectX 9, 11, or 12 APIs, dynamically adjust resolution or shading rates when certain user inputs are detected. Radeon Boost, available in select titles, takes advantage of the variable-rate shading hardware found in the RX 6700 XT AIB to punch up performance and reduce latency.

The RDNA 2 is a significant advancement from the previous generation and has an enhanced compute unit, a new visual pipeline featuring Ray Accelerators, and a new Infinity Cache.

The 96MB on-die cache results in frame data delivery with lower energy per bit. AMD claims it can deliver up to 2.5x the effective bandwidth compared to a 256-bit 12Gbps GDDR64 bus system.

Comparison of AMD’s RDNA and RDNA GPUs

 

The big news of RDNA 2 is the ray accelerators.

The RDNA 2 GPU’s compute units implement a ray-tracing acceleration architecture known as the Ray Accelerator. Ray tracing can be a very compute-intensive operation and to make real-time rendering practical AMD has added dedicated Ray Accelerators to its RDNA 2 GPU. The company claims it provides a massive acceleration for intersecting the large number of rays needed for realistic modern effects with the complicated geometry of the scene.

AMD says each Ray Accelerator is able to calculate up to 4 ray/box intersections or one ray/triangle intersection every clock. The Ray Accelerators calculate the intersections of the rays with the scene geometry as represented in a Bounding Volume Hierarchy, sorts them, and returns the information to the shaders for further scene traversal or result shading.

The other new DXR feature RDNA 2 brings out is Variable rate shading. VRS allows the hardware to focus the rendering work where it is most needed to deliver the most important visual cues in an image. AMD says their RDNA 2 variable-rate shading functionality is built throughout the entire pixel pipe. It offers shading rates of 1 x 1, 2 x 1, 1 x 2, and 2 x 2. AMD’s VRS allows for a unique shading rate to be selected for every 8 x 8 region of pixels. That very fine granularity and should enable developers to make better decisions as to the right shading rate for a given region.

The AMD Radeon 6700 XT has 12 GB of GDDR6

 

AMD’s FidelityFX is an open-source developer toolkit available on GPUOpen that AMD says makes it easier for developers to implement high-quality effects and optimizations while offering the best balance of visual fidelity and performance.

The first AMD effect, FidelityFX Contrast Adaptive Sharpening (CAS), launched in 2019 four new effects were added in 2020: Ambient Occlusion, Screen Space Reflections, HDR Mapper, and Downsampler.

AMD says FidelityFX is available in more than 40 titles today. A complete list of supported games along with information is here and the supported games can be found here.

We liked the thermal design of the RX 6700XT. The dual fans run smoothly and quietly (up to 4db lower noise compared to the Radeon RX 5700 XT at 35°C intakes) and go to Zero RPM fan mode under light load for silent operation.

As mentioned, the 6700 XT comes with 12 GB of GDDR6. AMD provided a list of the memory loads of some popular games to show how important a big framebuffer can be.

A list of games that have large video memory requirements can be seen in the table below.

Assassin's Creed Valhalla DX12Ultra High 6.4GB
Call of Duty Black Ops Cold War 11.1GB
Dirt 5 DX12Ultra High  9.5GB
Dirt 5 DX12Ultra High RT  10.0GB
Godfall DX12 Epic  7.4GB
Godfall DX12 Epic RT 11 8GB
Horizon Zero Dawn DX12 Ultimate  10.4GB
Red Dead Redemption 2 Vulkan Ultra  9.4GB
Shadow of the Tomb Raider DX12 Highest  7.4GB
Shadow of the Tomb Raider DX12 Highest RT  11.0GB
Watchdogs Legion DX12 Ultra  8.1GB
Watchdogs Legion DX12Ultra RT  9.5GB
(Peak video memory consumption
measured on RX 6700 XT 12GB at 1440p)

 

Performance comparison

We tested the Radeon 6700XT against an AMD Radeon 5700, an Nvidia RTX 3060 Ti, and an Nvidia RTX 3070.

The Radeon 6700 XT is also compatible with AMD CPU and BIOS-based systems that offer Smart Access Memory. In conventional Windows-based PC systems, processors can only access a fraction of graphics memory at once, limiting system performance. A core aspect of PCIe, the BaseAddress Register (BAR) defines how much discrete GPU memory space to map. In today’s PCs, processors only access a fraction of GPU memory, typically limited to 256 MB of mapped memory. With less efficient data transfer, performance is restricted. With AMD Smart Access Memory, PCIe bandwidth is utilized to expand the data channel to fully harness the memory removing the bottleneck to increase performance. We tested the Radeon 6700 XT on an Intel platform and so couldn’t test the Smart Memory feature.

We ran a series of tests at 4K and 1440P with Ultra to Very High Pre-sets.

3DMark DLSS Test 1440p Performance Assassins Creed: Valhalla 1440p Very High
3DMark RayTracing Test Assassins Creed: Valhalla 4K 
Bright Memory Infinite  Metro Exodus 1440p DLSS Off RTX Ultra 
Mesh Shader Feature Test Metro Exodus 1440p DLSS RTX Ultra 
Neon Noir Metro Exodus 4k DLSS off Ultra
Port Royal Metro Exodus 4k DLSS Ultra 
Time Spy Watchdogs Legion 1440p Very High
Time Spy Extreme  Watchdogs Legion 1440p VH DLSS Quality
  Watchdogs Legion 4K Very High RT-High DLSS Quality
  Watchdogs Legion 4K Vey High
  Wolfenstein Youngblood High 2560x1440 FXAA
  Wolfenstein Youngblood High 4K FXAA
Benchmark Suite used to test the RX 6700 XT

 

 

The raw scores we got are shown in the following table.

  RTX 3060 TI AMD 6700 XT RTX 3070  5700 XT 
Average FPS Intel 46.19 64.56 48.19 49.06
Average Score Intel 10319.25 7919.75 11049.75 5239.5

 

Then we calculated the Pmark, based on published power requirements and suggested retail price.

  RTX 3060 TI AMD 6700 XT RTX 3070  5700 XT
Power (W) 200 230 220 225
Price $399 $479 $499 $399

 

The Radeon 6700 XT Pmark based on the average benchmark score is low because of its price and power consumption.

 

Based on average FPS, even with a high price and power consumption, the Radeon 6700 XT comes out ahead

 

In raw power (TFLOPS) the Radeon 6700XT wins again

 

Priced between an Nvidia RTX 3060 Ti and 3070, but close to the 3070, the Radeon 6700 XT looks like a mid-range AIB at the high-end of the segment. The 6700 XT does not compare to Nvidia when it comes to ray-tracing and Nvidia's impressive DLSS technology, but mainstream gamers will be very satisfied with this AIB.

What do we think?

The hoarding and scalping of AIBs have driven up the retail ASP to artificial heights. We are sticking with the MRSP in our calculations and evaluations and segment distinctions, even though it doesn’t reflect today’s reality. We don’t like today’s reality and are considering burying our heads in the sand until things get back to normal and all the scalpers and hoarders die buried in their unsold AIBs.

If you could get a Radeon 6700 XT, it would be an excellent choice providing years of enjoyment.