AMD today introduced the Radeon RX 6800, 6800 XT, and 6900 XT graphics cards based on its latest RDNA 2 architecture. With a release date in November and prices starting at $580, AMD is aiming to compete directly with NVIDIA’s latest 30-series GPUs. And—better late than never—the RX 6000-series cards include a USB-C port to “power head-mounted displays with just one cable for a modern VR experience.”

Before we dive into details, here’s the release date, price, and basic specs of each card:

RX 6900 XT RX 6800 XT RX 6800
Price $1,000 $650 $580
Release Date December 8th, 2020 November 18th, 2020
Compute Units 80 72 60
Game Clock (GHz) 2.02 2.02 1.82
Boost Clock (GHz) 2.25 2.25 2.11
Memory (GDDR6) 16GB
Connectors DisplayPort 1.4 w/ DSC*, HDMI 2.2 w/ VRR*, USB-C* 2x DisplayPort 1.4 w/ DSC, 1x HDMI 2.2 w/ VRR, 1x USB-C
* connector counts unspecified

See a detailed spec comparison here

Based on its new RDNA 2 architecture, AMD is positioning its 6000-series cards to compete directly with Nvida’s latest 30-series GPUs in price, performance, and features.

Infinity Cache, Ray-tracing, and Smart Access Memory

New to the 6000-series cards, ‘Infinity Cache’ is 128MB of memory directly on the GPU die. AMD says the cache acts as a “bandwidth amplifier” for the rest of the card’s memory; 16GB of GDDR6 combined with the 128MB Infinity Cache increases “effective bandwidth” by up to 3.25 times compared to the same amount of memory without the cache.

“This global cache is seen by the entire graphics core, capturing temporal re-use and enabling data to be accessed instantaneously. Leveraging the best high frequency approaches from Zen architecture, AMD Infinity Cache enables scalable performance for the future,” the company explains.

The 6000-series cards also introduce hardware accelerated ray-tracing with one ‘Ray Accelerator’ per Compute Unit. The card’s ray-tracing tech is based on the DirectX 12 Ultimate implementation; AMD says developers can mix and match rasterization and ray-tracing effects, with “an order of magnitude” improvement in ray-tracing operations compared to the last generation of Radeon cards.

Image courtesy AMD

The company is also introducing a unique feature for users who pair AMD’s 6000-series GPUs with the company’s own 5000-series Ryzen CPUs. Called Smart Access Memory, the company says the feature allows the CPU to access more of the GPUs memory at once, resulting in a performance boost of a few percentage points depending upon the title. While not a groundbreaking change in performance by itself, it’s essentially ‘free’ (if you have the right combination of hardware), and a smart way to leverage the company’s broader hardware portfolio.

A VirtualLink to the Past

AMD’s own versions of the Radeon RX 6000-series cards include USB-C across the board, which, for VR in particular, would allow the cards to support the VirtualLink standard—a USB-C ‘alt-mode’ which was designed to provide VR headsets with data, power, and video through a single port.

Indeed, the company’s marketing says the port can “power head-mounted displays with just one cable for a modern VR experience,” though the timing is pretty odd given that the VirtualLink standard was initially introduced in 2018 and has since been abandoned. On the flip side, Nvidia was early with support for VirtuaLink by including USB-C ports on its first wave of RTX 20-series GPUs, only to eschew the power on the latest 30-series cards.

Still, as far as we know, a USB-C port on the RX 6000-series cards should mean that VirtualLink devices could work just fine, and headset makers could always devise their own single-cable headset connection based on the card’s USB-C port.

Variable Rate Shading

Image courtesy AMD

The RDNA 2 architecture of the 6000-series GPUs also supportS Variable Rate Shading which allows fine-grain control over the shading rate from one frame to the next. This can be used to essentially lower the resolution of some parts of the scene (say dark areas or those without much detail) while maintaining full resolution in important, or high detail parts of the scene.

For VR headsets specifically, the Variable Rate Shading feature opens the door to more precise foveated rendering, which could be static (to match lens distortion) or active (to align with eye movement). AMD hasn’t shown its own VR-specific solution (like Nvidia’s Variable Rate Supersampling) but the underlying tech to support this kind of foveation is there under the hood.

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We’ll be looking forward to getting our hands on AMD’s 6000-series cards to see how they handle upcoming high-resolution headsets like HP’s Reverb G2 and memory hungry games like Microsoft Flight Simulator (2020).

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Ben is the world's most senior professional analyst solely dedicated to the XR industry, having founded Road to VR in 2011—a year before the Oculus Kickstarter sparked a resurgence that led to the modern XR landscape. He has authored more than 3,000 articles chronicling the evolution of the XR industry over more than a decade. With that unique perspective, Ben has been consistently recognized as one of the most influential voices in XR, giving keynotes and joining panel and podcast discussions at key industry events. He is a self-described "journalist and analyst, not evangelist."
  • Ad

    VRS seems useful not for foveation in the usual sense but for exactly what it’s usually used for. A depth independent approach like VRSS was completely useless or even made performance worse. When darkness, far away objects, etc all affect VR visibility as much or more, why not just use the usual methods?

  • Pete Mitchell

    HDMI 2.2?

    • dk

      xD truly next gen
      and apparently DisplayPort 1.4a “According to AMD, these cards have been upgraded to support HDMI 1.4a but without the 3D features brought forward by UVD 3.0.”

  • Jistuce

    The USB-C port is probably configured for DP Alt Mode rather than VirtualLink. Which is a configuration someone can use today, and VirtualPort should’ve just been DP Alt Mode anyways.

    • Hokhmah

      The biggest issue with DP Alt Mode (and DP in general) for VR is that you don’t have any sort of audio input channel. That’s why you need an additional USB connection for the Mic and also cause DP doesn’t deliver enough power to drive the headset. From what I know both things would be solved with VirtualLink.

      • Jistuce

        DP Alt Mode still has USB-C Power Delivery.
        And USB data provides a convenient option for audio input. (DP Alt Mode always has USB2 data available, and depending on configuration, CAN have USB3 data available alongside DP data.)

        • Hokhmah

          Hmm, you’re right. Then DP Alt Mode would really be a viable option.

  • Gamer

    RIP RTX 3000

    • Dead Monkey Bounce

      Naturally retarded or do you have to work at it?

  • Andrew Jakobs

    Still think USB-C port should have been standard for all new video devices.. On connector for even more stuff is so much better..

    • Erilis

      Sounds good to me. Can it run a 4k panel at 144hz? I know I can just google that and find out, but if it doesn’t, it’s not ready for primetime

    • Svlad Cjelli

      DisplayPort 2 has 80 Gbps raw bandwidth.
      USB-C 3.2 only supports 20 Gbps max.
      You couldn’t run 4k@144hz over USB-C 3.2
      edit: technically you can’t even run 4k@60hz over USB-C 3.2, as it requires just a hair over 20 Gbps at ~21 Gbps.

      • Joshua

        You are confused as to how USB-C Alternate Mode works. It does not encapsulate the DisplayPort over the USB protocol. It only uses the USB-C connect to sent DisplayPort data directly over the USB-C cable. A USB-C cable has 4 data lanes, the same as a DisplayPort cable. It is DisplayPort signals sent across the USB-C wires, not USB signals.

        USB-C is merely a type of connector. It does not impute any characteristics about what kind of transmissions travel across the line. (except for insertion orientation.)

        There is no such thing as USB-C 3.2. There is USB 3.2, and USB type C connectors. What is special about USB-C is that the connections can provide high-quality electrical connections suitable for the transmission of high-bandwidth signals (not just USB signals), as well as up to 100W of power, and the wires are electrically compatible (the insulation and pairing) for being used different ways.

        So you could have 3 of the 4 lanes carrying DisplayPort signals, assuming DP can manage with 75% of maximum bandwidth for the version of DisplayPort in use, and then the 4th lane can be used to transmit a USB 3.2 SuperSpeed (5Gbps) connection.

        This is the same way Thunderbolt3 can use USB-C connectors, to transmit Thunderbolt3 signals over the wires, and have a maximum throughput of 40Gb/s with 4 lanes, but not really using USB 3.2, but just using the USB type-C connector. This is solely due to better signaling of the TB3 protocol, since it is able to get 10Gbps out of each of the 4 lanes, while USB 3.2 can only get 20Gbps in a 2×2 configuration.

        However, USB4 will be able to work the way you are thinking, by “tunneling” these different signals as packetized data, very much like ThunderBolt 3 does. This page is very instructive: DataPro’s USB4 Guide and FAQ

  • Trip

    I’m highly skeptical, but hopeful that these cards will stack up as favorably against the 30 series RTX cards.

  • Ahahahhaha, The VirtualLink…. AMD is implementing it now that it is dead… it is pretty funny :D

    VirtualLink was a great idea, but if headsets manufacturers are not implementing it, it is pretty useless.

    • Sven Viking

      If it had been on the 3000 series cards it might have had a chance, but nobody’s going to implement it if anyone with a recent Nvidia card needs an adapter.

    • redhat

      As long as it helps with Oculus Link it does not necessarily have to implement Virtual Link anyway.

    • Erilis

      I don’t get virtual ink, now that i’m looking back. It’s just a USB-C just as good as any USB-C. I get that video signal isn’t ported back to motherboard and then out to headset, but anyway, another usb port, just leave it there.

      I would think twice about getting a AMD graphics card for running VR. VR titles aren’t the biggest titles, most optimized apps there is. Even squadrons squandered it up with optimization on PC. Developers would be so overwhelmed, they won’t even get to AMD cards.

      Run non-RTX pancake games on an AMD card until the cows come home. Anything else, NVIDIA

      • Randall C

        I can’t believe you still believe that crap about AMD being less. You must also think Macs are better for creative people, too.

    • saintkamus

      The only reason nVidia removed it, is because their boards are fucking vampires. This would’ve added another 30W to the already ridiculous power draw the 30 series has.

      • Dead Monkey Bounce

        yeah about the same as the Big Navis

    • Herbert Werters

      Ahahahhaha, NVidia is no more an option for VR with 10GB of VRAM. lol

  • MeowMix

    Isn’t AMD’s RDNA encoder slower than Nvidia’s ? Won’t that mean lower performance for streaming based headsets: Quest 1 and Quest 2 via Link and VD. I believe ggodin had mentioned this point in the past.

    • Hokhmah

      At least the one in RDNA1 cards, yes. Don’t know about the new cards though and if there will be some sort of upgrade in quality and performance.

  • dk

    it’s an error ….2.1 is coming out now

    • Sinshi Uzumaki

      Yeah. I thought so. Thanks

  • Hokhmah

    VirtualLink was a “dead horse” from the beginning for several reasons. First off I wouldn’t mind all future devices using an USB-C connector and signals/standards being negotiated depending on built-in chips, capabilities and needs. Instead of having DP, HDMI, VirtualLink, … just give me 4-5 USB-C ports that all have the same supported standards. The rest is negotiated by the connected devices.

    That said, VirtualLink doesn’t make any sense at this point cause of in which direction (PC)VR develops and what the next goals are. Present and soon to be released headsets in 2020 and 2021 rely mostly on DisplayPort, but Quest 2 or projects like DecaGear show where the journey is going -> wireless.

    Also now making a headset with VirtualLink support doesn’t make any sense for the companies. VR is still a niche market and distributing a headset with a connector that most GPUs don’t have will make it very unattractive. Even if you allow for DP or VL, you would need to implement it and ship two different cables which will just drive the costs/price up.

  • Brenden Neufeld

    reading into the bandwidth of the ports, hdmi 2.1 supports 48Gbps, while display port supports 32.4Gbps, i thought display port was the better option but it appears thats not the case anymore or am i missing something?

    • Dead Monkey Bounce

      yeah you forgot DP 1.4 and DP 2.0