// PC GAMER — GAMING
RimWorld drops Unity for its own in-house engine, says your saves still work, so do most mods, and the whole thing runs twice as fast
When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.
"We’re announcing update 1.7, which moves RimWorld from Unity to the Waylith Engine, our own in-house engine built by Ludeon Studios. The game looks and plays exactly the same, but in our tests performance is improved by 2-4x.
"You can try 1.7 right now on the unstable beta branch… We stress-tested a late game colony and saw 2.2x better performance on 1.7 compared to 1.6. A modpack with 1,500 mods (!) went from 14 minutes to 6 minutes to load. (These are just our results; individual performance improvements may vary due to your specific PC or mods.)
"Your 1.6 savegames will load on 1.7, and 1.7 saves also work if you go back to 1.6."
Those are some 'wipe your glasses, rub your eyes, triple-check you did the maths right' numbers that RimWorld's new Waylith engine is spitting out, but it seems to be the real deal. Over on Reddit, players who are trying out the new engine are finding impressive results: "Stable 120 fps and 900 [ticks per second]. Normally I have at max speed 60/700ish," says TheLemonFox. "Impressive." Though they also report the new build is RAM-hungry: "it eats RAM like there is no tomorrow. 12-13 GB RAM directly at startup is… something."
Another user attempted Ludeon's own modpack feat, loading 1,477 mods into the game and hitting go, reporting a decrease in time to load from "at least 30 minutes" to six minutes and 17 seconds.
It's fairly mind-boggling and very impressive, especially given save games and even the majority of mods can be happily bounced back and forth between RimWorld's previous Unity version and its new Waylith iteration. I'm not sure what dark gods Ludeon has been communing with, but it seems like a worthwhile deal.
Oh, and the studio signs off with a little tease: "RimWorld isn’t the only game on Waylith. We’re working on something new! It may be a little while before we can share more details, but we couldn’t resist telling you."
2026 games: All the upcoming gamesBest PC games: Our all-time favoritesFree PC games: Freebie festBest FPS games: Finest gunplayBest RPGs: Grand adventuresBest co-op games: Better together
Keep up to date with the most important stories and the best deals, as picked by the PC Gamer team.