You’re not supposed to connect an external GPU to the Steam Deck, but someone did it anyway.
YouTuber ETA Prime not only managed to get it working, but was able to play games like Elden Ring at 4K with maxed out settings. Valve has repeatedly said that external graphics cards aren’t compatiblebut ETA Prime was able to make it happen anyway.
Steam Deck Using an External Graphics Card – Screenshots
They managed it by utilizing the Steam Deck’s M.2 PCIe x4 socket, which is normally meant for storage. ETA Prime used an external graphics card M.2 dock that plugs into the storage socket at one end and the graphics card at the other end. While that only allows the Steam Deck to use four lanes of PCIe, it still worked regardless. To complete the “build”, ETA Prime connected both the M.2 dock and graphics card to a standard ATX power supply.
Since the native SteamOS does not support external graphics cards, ETA Prime had to boot Windows 11 off of a microSD card. Finally, he used a USB-C hub to connect accessories like a mouse and keyboard.
He tested a range of graphics cards from the Nvidia GTX 1060, GTX 1650, RTX 3060, Radeon RX 590, RX 480, and RX 6900XT. Unfortunately, none of the Nvidia cards worked, perhaps due to the AMD architecture used in the Steam Deck.
After running a bevy of AAA games, he was able to average between 40 and 108 frames per second depending on the game. The Witcher 3 was able to run well over 100 frames, while other games like Elden Ring and Cyberpunk 2077 managed between 40 and 50 frames per second.
The entire APU inside the Steam Deck is rated between 4W and 15W of power. That means that though it’s using AMD’s latest Zen 3 CPU architecture, the lower power ultimately limits how fast the CPU can run. This creates bottlenecks for demanding games, especially ones that require more CPU power such as open world games.
Obviously, this is not something that most people should do. The whole point of the Steam Deck is to be portable. That said, one of the selling points of the Steam Deck is the ability to plug into an external monitor and play using a traditional mouse and keyboard setup. It does not seem too far-fetched to see if Valve includes external GPU support in the future.
Our Steam Deck review was mostly positive with major points being given to the ability to play a good chunk of our backlog of Steam games anywhere. However, we also noted that it still has a long way to go with several bugs and launch issues that hamper the experience. Fortunately, if you’ve already preordered the Steam Deck, Valve is ramping up shipments and is allowing people to finalize their order.
David Matthews is a freelance writer for IGN.