Testing PC games using FEX on a high-end Android tablet can yield playable results — but the early tech is still not ready for prime time

$1,700 liquid-cooled phone can run GTA V at up to 100 FPS, Red Dead 2 at 50+ FPS via emulation

Resident Evil 3 , by contrast, offered a much smoother experience when running the title at 720p. With settings locked in and the application allowed to access the large RAM pool of the RedMagic Astra, I was able to play the introductory segments of the title with little to no issue. That should come as little surprise to anyone who knows that Capcom’s RE Engine scales incredibly well with lower-end devices, especially if they are limited in scope, such as Resident Evil 3 – I wouldn’t chance running a heavier, open-map title like Monster Hunter: Wilds on here so soon.

With the game up and running, I then pushed the image quality with settings set to prefer performance, with no upscaling. Resident Evil 3 stayed at a steady 40- 60 FPS for most of the introductory segment, and only when dealing with more challenging scenes with multiple light sources and particle effects did our frames begin to drop to lows of around 27 FPS. That’s still playable, though not quite offering a perfect experience, and some subjectivity comes into play. Following this, testing the ‘Prefer Graphics’ preset with no upscaling, we reached a range of 25-42 FPS, which is again, more than playable enough for a single-player title. While you’re not going to get that ideal 60 FPS target, the game also doesn’t look like you’re playing it through a vaseline filter, which is a plus.

With Resident Evil 3 producing solid results, I marched on to Clair Obscur: Expedition 33 . This Unreal Engine 5-based title was a tricky one to get up and running. Firstly, I had to set the lowest possible internal resolution, then select the correct drivers to get things set up. Following that, we were in the game. But there was one glaring issue: Image quality. The selected graphics driver (nor any other combination) actually yielded anything that remotely looked like Clair Obscur , with textures going haywire and environments missing some textures entirely. This one was a total, unplayable mess; even measuring its performance would have been a waste of time. So, what’s going on under the hood, and why is performance so variable between titles?

To understand why individual titles run so differently is to understand that each game runs a wholly different engine. CD Projekt Red’s RED Engine has proven to scale to systems like the Steam Deck and Switch 2, but performance in-game on the RedMagic Astra has yet to match either a Steam Deck or a Nintendo Switch 2 in image quality.

For Expedition 33 ’s Unreal Engine 5, this is a complicated nightmare. The CPU translation layer, in addition to DirectX12’s VKD3D translation, is what’s causing things to not load correctly, such as DX12’s mesh shaders. To put things simply, there’s a complex stack of operations required to run things smoothly, and when those graphical pipelines get as complex as a modern title, like Clair Obscur , the house of cards begins to fall down.

This isn’t a problem for Resident Evil 3 ’s RE Engine, which uses a lighter and cleaner implementation of DirectX12, especially when compared to Unreal Engine 5. You also have the option to launch with the DirectX 11-based DXVK, which, in itself, is much easier for a translation layer to handle than the more complicated VKD3D. The caveat here is that you’ll have to access a different legacy beta branch to enable that, as the main branch of the title forces DirectX 12.

Worsening things is the fact that so much of this support relies on community-developed graphics drivers, most notably, custom “Turnip” drivers, based on the open-source Linux Mesa project, which patches Vulkan extensions that are actively still being reverse-engineered by the developers. These optimizations get missed by the official Qualcomm system drivers, which are closed-source. Therefore, as demonstrated in Clair Obscur: Expedition 33 , when Turnip drivers are met with complex shader pipelines from UE5, the GPU driver can fail to render geometry correctly, even if the title boots.

Many titles that do not require the usage of such demanding graphical pipelines can work without breaking much of a sweat: So, if you’re missing out on Slay the Spire , or Hollow Knight: Silksong , those titles are demonstrably stable using FEX and emulator apps like GameNative. For our tests, we wanted to see how FEX handled complex shaders, graphics, and modern “big-budget” experiences.

In and of itself, FEX is an ongoing project, and we’re not going to see major miracles happen overnight when it comes to elements out of the project’s scope, such as Qualcomm’s development of official drivers that officially support mainstream games.

Qualcomm’s mobile chips were built strictly to run mobile apps and games, meaning that adding the wrinkle of supporting elements like desktop-level Vulkan instructions is a use case they simply never really considered supporting before. If the company wants to capitalize on the work being done by the FEX team, Qualcomm-based chips must also come with similar levels of support as desktop graphics drivers, and the likelihood of that happening is quite slim indeed. As of the time of writing, community drivers for specific titles can enhance the experience of some titles, if you're willing to go to those lengths.

While the efforts of FEX-Emu and its complex, layered translation to get things running are indeed impressive, you’re not about to be able to take your whole Steam Library with you anywhere, until there’s more maturation of these applications and the community-made drivers (potentially with the help of a company like Valve) to create workarounds, or dedicated drivers. For now, it’s still too early to start throwing FEX out as a feature in a mainstream product until all of those rougher edges, like driver support, are smoothed off for end-users. Anyway, my tablet’s back to being relegated to being a very fancy comic-book reader again until the entire software pipeline has matured.

Sayem Ahmed is the Subscription Editor at Tom's Hardware. He covers a broad range of deep dives into hardware both new and old, including the CPUs,\u00a0GPUs, and everything else that uses a semiconductor. ","collapsible":{"enabled":true,"maxHeight":250,"readMoreText":"Read more","readLessText":"Read less"}}), "https://slice.vanilla.futurecdn.net/13-4-20/js/authorBio.js"); } else { console.error('%c FTE ','background: #9306F9; color: #ffffff','no lazy slice hydration function available'); } Sayem Ahmed Social Links Navigation Subscription Editor Sayem Ahmed is the Subscription Editor at Tom's Hardware. He covers a broad range of deep dives into hardware both new and old, including the CPUs, GPUs, and everything else that uses a semiconductor.

Testing PC games using FEX on a high-end Android tablet can yield playable results — but the early tech is still not ready for prime time

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