TL;DR: We’ve established that Doom can run on a potato, but what about something more complicated? A modder recently tried running Half-Life 2 natively on a Raspberry Pi 4. The initial results look rough but show potential for a theoretical expansion of Valve’s platform support.
Videos posted on Reddit this week show sections of Half-Life 2 running natively on a Raspberry Pi 4 and an Apple M2 Macbook Air. Redditor zbios said the demo’s primary goal wasn’t to test the Raspberry but to see if Valve’s Source engine could run on Arm platforms.
Before getting overly excited, know that the microcomputer doesn’t run Valve’s seminal 2004 first-person shooter well. The game manages around 15-to-20 frames per second, with the graphics set to a mix of low and high settings at 720p.
At 1080p, the framerate can fall as low as 10fps. The game may look barely playable, but it’s stable enough to prove that a Source engine game can run on an Arm-based Linux system, which was the Redditor’s primary goal.
The project was possible thanks to the 2018 Team Fortress 2 source code leak, which led to a version of Valve’s engine becoming freely available on GitHub. That code’s support for every Arm-based system except Windows on Arm allowed zbios to port Half-Life 2 to the Linux-based Raspberry Pi 4.
The modder subsequently used the RP build to mod the game for Apple’s M2 silicon, unsurprisingly handling the game much better. The beginning of the Revenholm section managed 300-400fps, further proving the possibilities of porting Source engine games to Arm. According to zbios, converting Portal should also be possible, but comments on the GitHub page indicate Garry’s Mod is out of reach due to its modifications to the engine.
These successful demonstrations raise the question of whether Valve could offer Arm-native versions of all of its Source engine games on Steam, like DOTA 2, Counter-Strike: Global Offensive (which may receive a sequel or major update soon), and Portal 2. Perhaps they could join the already extensive list of games on Steam that run natively on Apple Silicon. Additionally, Nvidia Lightspeed Studios released Android versions of Half-Life 2 and Portal for the Nvidia Shield in 2018, proving that the foundation for Arm support exists.