Path tracing requires powerful hardware to run, even with tools like DLSS and Frame Generation. Rendering fully path-traced environments shouldn't be possible yet, but here we are - with the path-tracing transforming games like Cyberpunk 2077, Alan Wake II, and Portal with RTX. The latter is a mod created by NVIDIA using its new and powerful RTX Remix platform - and when it debuted, you needed a GeForce RTX 4080 or RTX 4090 for it to be playable.
At a higher resolution with 'ultra' settings, that is, because someone managed to get a playable version of Portal RTX running on a Steam Deck - Valve's portable gaming PC handheld powered by a custom AMD mobile SoC.
The video demonstration by NightSightProductions is a great reminder that when you can tweak settings, you can get a demanding game to run on a wide range of hardware. However, in the case of Portal with RTX, there's some serious tweaking going on alongside the resolution being dropped to 864 x 486 to hit a playable 30 FPS.
In addition, secondary bounces for the path-traced lighting are turned off (by default, multiple bounces are required to give the game its impressive visuals) - the full 'ultra' version has four bounces per ray. So, the lighting isn't up there with a version running on a GeForce RTX 4090. Or even a GeForce RTX 4060.
This darker, low-res version of Portal with RTX still looks good, which is a testament to what path tracing brings to the table. When it comes to ray-tracing and path tracing, lowering the resolution and pairing the tech with upscaling tools like DLSS and FSR is the key to unlocking performance.