AMD has had quite the year! Not only did we see the release of the Radeon RX 5600XT into the wild in the first quarter, we saw the Ryzen 4000 series explode into the mobile space and the Ryzen 5000-series create a huge upset in the desktop CPU market. Some might call this luck, but in the face of NVIDIA’s RTX 30-series, could AMD’s long-awaited “Big Navi” GPU respond in turn?
Strap in, because this is one of two articles on the AMD Radeon RX 6000-series, covering the RX 6800 XT within this article. We will be covering the RX 6800 here. Because of the shared architecture and similar features set, some of the information will be shared across the two reviews, with the lion’s share of nuance found within our benchmarking section and final
After a long wait, we are about to find out if 2020 is AMD’s year as the “comeback kid,” or if we are left wanting Big Navi to be bigger.
Specifications
- MSRP: $649 USD
- Compute Units: 72
- Stream Processors: 4608
- Game Clock: 2015MHz
- Boost Clock: 2250MHz
- Memory Type: 16GB GDDR6
- Memory Bandwidth: 256-bit
- Memory Cache: 128MB L3 cache
- Power Requirement: 300W
AMD has been very open about its multi-year roadmap for their Zen processors and RDNA GPUs. With each announcement and each iteration, Dr. Lisa Su voiced AMD’s love for gamers and its commitment to make AMD the ultimate platform for gaming. And that has been quite evident in the past year. Whether gaming on a console or PC, AMD has made a strong for itself, especially when it comes to CPUs.
With the release of the Radeon RX 5000-series, AMD created the RDNA architecture - effectively called Navi. Navi-based GPUs maximized performance per watt over the previous generation and did something pretty incredible in a market of extremes: it offered an affordable GPU upgrade path for users looking for raw performance boost in rasterization. However, RDNA was missing some key features that consumers wanted: 60 frames per second (or greater) at 4K resolution and real-time raytracing.
As it continues to move further along its roadmap, AMD’s Radeon RX 6000-series improves upon the RDNA formula with RDNA2. Utilizing the same 7nm process, RDNA2 packs in double the Compute Units, increases the clock speed frequencies and offers a feature never before found in a GPU architecture: a L3 caching system.
This L3 cache, called Infinity Cache by AMD, offers 128MB of memory outside of the GPU’s GDDR to assist in rapid processing in render times. Built using AMD’s high-density EYPC Server SRAM, the Infinity Cache offers quick access to recently processed scenes, keeping it adjacent for speedy recall. This means lower latency between the GPU and its GDDR, making its operation more power efficient by lowering memory bandwidth for similar operations.
With the power efficiency of the Infinity Cache and the lower memory latency it provides, AMD is able to push clock speeds into blistering new heights while keeping the GPU’s power needs below 300W on the higher end of the RDNA2 product stack. And all of this spells good news for the features missing from RDNA’s maiden voyage. After all, AMD has promised with RDNA2 is to deliver higher performance per watt and than RDNA while making the RX 6000 series AMD’s go-to platform for 4K gaming. We will get into that more in-depth in our benchmarking section.
When it comes to raytracing, AMD’s philosophy has been this: to work with existing tools to enable more developers the ease of use for the platform (such as DXR/DirectX 12 Ultimate, Vulkan, etc.) while providing the hardware to support it. With that in mind, each RDNA2 GPU contains 1 ray accelerator per compute unit within the architecture. The ray accelerators working in tandem with compute units for features like ambient occlusion, denoising, and variable rate shading.
By working within this framework, AMD believes that it can strike a balance between visual fidelity and performance, but they do recognize the burden that hardware-based ray tracing put onto a GPU. Where NVIDIA has improved their RTX experience with Deep Learning Super Sampling (DLSS), AMD is prepared to answer with FidelityFX Super Resolution. While the technology is not fully integrated at this point, AMD is working to release it in the near future.
But that isn’t all. Remember Dr. Lisa Su’s comment about AMD providing the ultimate gaming platform? It wasn’t just about high performing CPUs and GPUs, but the synergy between them. Taking a page from their mobile platform playbook, AMD is bringing a feature called Smart Access Memory to Ryzen 5000-based systems. By utilizing the speeds of PCIe 4.0, Smart Memory Access gives the CPU access to the GPU’s memory, removing I/O bottlenecks to increase performance. According to AMD, this technology can increase performance at 4K by an average of 6%.
With all of this put together, RDNA2 is poised to cause an upset in the upper end of the GPU market. Let’s see just how it performs in practice.
Test Bench Information and Methodology
Before we get into the numbers, here are the system specifications for our test bench:
- CPU: AMD Ryzen 7 3800X
- Cooler: Corsair Hydro Series H150i ELITE CAPELLIX (Closed loop cooler)
- RAM: Zadak SPARK 32 GB 3200MHz DDR4
- Motherboard: ASUS Prime X570-Pro
- Storage: 500GB Samsung 980 PRO, 1TB WD_Black SN750, 1 TB Seagate FireCuda
- PSU: NZXT E850
- Case: Corsair 4000X
For our testing, we will be looking at data collected from benchmarks across a series of tests which utilize a diverse range of APIs. This will give a broad overview of how the RX 6800 XT will perform.
Within our charts, you will see MSI’s Radeon RX 5700XT Gaming X and the RTX 2080ti Founders Edition GPUs to show the top tier GPUs from the previous generation product stacks alongside offerings from the RTX 30 series. Since we are dealing in “flagship” territory, we will be focusing our 30-series comparisons with the RTX 3070 and RTX 3080. Standing in for the 3080 is the GIGABYTE RTX 3080 Gaming OC 10G and for the 3070, we have NVIDIA’s Founders Edition. You will also see numbers for AMD’s Radeon RX 6800, but we will be focusing on those in an article of its own. We are also withholding a comparison with the RTX 3090 because that fight is for another day.
It is also important to note that these comparative numbers are not using the RX 6800 XT’s Rage Mode or AMD’s Smart Access Memory. Rage Mode offers safe overclocking via AMD’s software while Smart Access Memory opens up CPU access to GPU memory when a Radeon RX 6000-series GPU is paired with a Ryzen 5000-series CPU. The motherboard for our test bench did not have a BIOS update available at this time of the review.
With all of that out of the way, let’s dive in.
Synthetic and Gaming Benchmarks
Right out of the gate, the RX 6800 XT comes swinging. Much of the conversation surrounding both AMD and NVIDIA’s GPU launch has swirled around performance compared to the venerable RTX 2080ti. In most of our gaming tests, the RX 6800 XT handily takes the 2080ti to the mat and puts a +20% performance average delta between the two in both 4K and 1440p tests.
The story is quite similar to the RTX 2080ti’s budget-friendlier successor, the RTX 3070. The RX 6800 XT takes a steady lead in many of our test titles… again. After comparing the number, we see an average performance increase of around 23% at 4K and around 19% at 1440p. But neither of these GPUs are AMD’s target.
The RX 6800 XT’s true rival is the RTX 3080. It trades shots in rasterization winning some and losing others while both averaging within ~6% of NVIDIA’s flagship at 4K and creeping right beside its performance at 1440p. Most impressive of these data points is that the RX 6800 XT beats the RTX 3080 on NVIDIA’s turf in Shadow of the Tomb Raider! As bitter a loss as it is on NVIDIA’s side, in Far Cry 5, the RX 6800 XT falls far behind in an engine that typically favors AMD.
Things get even more interesting when we look at a synthetic benchmark like 3DMark’s Time Spy. The RX 6800 XT absolutely smokes the 2080ti’s 4K performance with a 38% advantage while leading the RTX 3070 by 28%. Keeping in step with these numbers, we see the RX 6800 XT overtake the RTX 3080 by 7%. Interestingly, at 8K both the RX 6800 XT and the RTX 3080 are within 1% of each other's performance.
In all of this data, we have yet to talk about the performance uplift between the RX 5700XT and the RX 6800 XT. If you’re keeping track of the numbers, we see a whopping 112% performance leap in 4K performance in 3DMark’s Time Spy with an average of around 90% games using traditional rasterization.
With all of this in mind, the question remains: can it ray trace?
Real-Time Raytracing Performance
As mentioned above, AMD’s approach to real-time raytracing is vastly different than NVIDIAs. Whereas NVIDIA’s approach is a little more boutique, AMD’s preference is to work within the sandbox of tools largely available to developers, hence their raytracing support with DirectX 12 Extreme (or DXR) and Vulkan. As a result the tests that overlap are limited for the time being. However, we do have a few titles that highlight the state of real-time raytracing performance.
At 4K, while the RX 6800 XT comes within a few frames per second of the RTX 2080ti and RTX 3070 in Control, it looks a bit lackluster across the competition. The story is similar at 1440p, but the RX 6800 XT does make the case for itself that it can, in fact, average 4K at 60FPS with raytracing enabled.
But there is another side to this story: The data collected from the RTX 20- and 30-series GPUs within these charts include the Performance Mode uplift from DLSS 2.0.
As things stand, the RX 30-series does outperform the RX-6000 series, but it has significant help. When AMD’s FidelityFX Super Resolution fully releases into the wild, we could see widespread adoption across the gaming APIs, with or without the presence of real-time raytracing, giving a performance bump all around!
Thermal Performance and Acoustics
With a cooling design reminiscent of NVIDIA’s RTX 20-series, the RX 6000-series does what it has been doing the entire time: improving upon performance… at least, over the previous generation. The acoustic performance of the RX 6800 XT is interesting. While the fan noise was not any louder than normal case fans, it was noticeable when the fans were about to ramp up. It isn’t unpleasant, but it is not quite.
While the RX 6800 XT we received from AMD does not quite have the cooling capabilities of MSI’s RX 5700XT Gaming X, it does keep temperatures managed within the high 70C range. We did have a few moments where we saw the RX 6800 XT jump into the 80C range, but not near enough to have us concerned about thermal throttling, even while utilizing AMD’s overclocking Rage Mode.
Final Thoughts
Big Navi represents a huge swing at the competition with the Radeon RX 6800 XT. While it doesn’t quite overtake the RTX 3080, it does go toe-to-toe in rasterization performance at 4K. Not only that, the RX 6800 XT reduces the margin in average performance between the two at 1440p to next to nothing.
Speaking of 1440p, that seems to be AMD’s target performance point for real-time raytracing at the moment. Performance in DXR-enabled applications did average above 60 frames per second at 1440p, but 4K left us wanting for more. We tried to see if AMD’s Rage Mode would help us out, but it did little to move the counter.
It is important to keep in mind that these numbers have no “secret sauce” helping boost their performance - that’s pure beef from the GPU. We saw a similar situation with NVIDIA’s 20-series when the first RTX titles were released. AMD’s forthcoming FidelityFX Super Resolution solution could be the ticket to enhancing performance, much like DLSS 2.0 has done for RTX.
Coming in at $649.99, the Radeon RX 6800 XT is a beast. It puts AMD within striking distance of their competition’s flagship GPU in both price and raw performance. Not only that, AMD isn’t content to play catch-up, the RDNA2 architecture behind the RX6800 XT pushes the possibilities of what a GPU can do. We are excited to see the doors that Smart Access Memory can open in terms of CPU/GPU synergy, how developers will take advantage of the Infinity Cache, and what all of these advances in technology could mean for game performance in the future!
If the maturation of Ryzen CPUs over generations and RDNA2’s first showing are any indication of where AMD is going, the RX 6800 XT may just be the herald of a new era for Radeon graphics and we are here for it!
Don’t call it a comeback; AMD has been here for years… and their game is stronger than ever.
