Steam Deck Tested with External Radeon RX 6900 XT GPU

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Image: Valve

The Steam Deck is a powerful and popular handheld gaming system. From its open-source design to APU, it holds a lot of promise for tinkerers. One person has attached an AMD Radeon RX 6900 XT. A video shows the handheld running games in 1080p and 4K, some well above 60 FPS, with the steps for getting the two devices working together.

We attached an external GPU to the steam deck and it works! In this video, we see how the steam deck performs with an external M.2 Video card. The Radeon RX 6900XT is overkill for the steam deck but I could not get any Nvidia Graphics card working yet so the 3080 and 3090 were out of the question for now. So can we game at 4K on the steam deck with an external Video card attached? Let’s find out. By the way we did have to use WIndows 11 on The Deck for this to work right now

The process isn’t convenient, requiring the handheld to be opened and more. The GPU also needs its own power supply. These steps are not too much for PC builders, but it would be more work for others. This is more of a proof-of-concept for showing off its potential.

A first step is to remove the M.2 SSD and attach an adapter to connect the GPU. Windows 11 is then installed on a microSD card. Then it is just a matter of booting it up.

There are some bottleneck issues with the Steam’s APU, but the benchmarks are still pretty impressive. Some of the varying framerates were due to using the M.2 slot for the GPU.


  • The Witcher 3 – 90~108 FPS on Ultra setting
  • God Of War – 30~48 FPS on Ultra setting
  • GTA V – 60~70 FPS on Very High setting


  • Cyberpunk 2077 – 40~80 FPS on High setting
  • Elden Ring – 46-52 FPS on Max setting

Some suggest Valve may be considering a Thunderbolt port for the next Steam Deck, although that would need a more powerful APU. Throw in an external GPU enclosure, and one would probably have all the basics covered.

Source: VGC

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Peter Brosdahl
As a child of the 70’s I was part of the many who became enthralled by the video arcade invasion of the 1980’s. Saving money from various odd jobs I purchased my first computer from a friend of my dad, a used Atari 400, around 1982. Eventually it would end up being a lifelong passion of upgrading and modifying equipment that, of course, led into a career in IT support.

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