In context: Arkane's latest immersive sim-slash-shooter-slash-stealth-'em-up, Deathloop, released mere days ago to rave reviews (for the most part). As is often the case with Arkane games, Deathloop's PC version has suffered from a few nagging performance problems since its September 13 release. To be specific, some customers have been plagued by frustrating stuttering issues they can't seem to fix themselves.
Fortunately, an end to these problems could be in sight at long last, thanks to the efforts of everybody's favorite gaming graphics tech YouTube channel Digital Foundry (as well as Deathloop's developers themselves).
DF's Alex Battaglia covers all of the latest details regarding Deathloop's PC performance optimization in the video below, among other things, such as how Deathloop's PC port stacks up against its PS5 counterpart. However, the latter isn't the relevant bit for now.
What is relevant to us is why Deathloop seems to be stuttering on PC at all. As Battaglia & co discovered, it is not, generally speaking, because the game is making poor use of your system's resources. In fact, he says, Deathloop boasts fantastic frametimes, with no stand-out CPU usage problems to speak of (on average hardware, anyway). There are a couple exceptions, which he points out, but that is generally the case.
What people are reporting as stuttering, he says, is actually caused by an unusual mouse movement bug that can present itself regardless of whether you run the game at a locked 30, 60, or 120 FPS (or even if you don't lock at all and use G-Sync or FreeSync to manage hitching). When you move the camera, it occasionally stops outright for a frame -- unfortunately, that's a big enough hitch for many users, myself included, to notice and subsequently complain about.
So, what's the solution? Prior to yesterday, there wasn't one, really. However, if you're willing to delve into the oh-so-dangerous (not really) realm of hotfixes, Arkane now has a partial answer. By opting-in to Deathloop's latest beta patch (Battaglia explains how to do so at roughly the 5:38 mark above), you can eliminate the mouse jittering when running at a locked 30, 60, or 120 FPS.
Unfortunately, the issue is still present for those running on a variable refresh rate (VRR) monitor, using tech like the aforementioned G-Sync. Hopefully, Arkane will close that last little gap soon. It's evident that they're aware of the problem, at least.
So, TL;DR: how do you fix Deathloop's PC "stuttering"? Download the latest beta patch on Steam, lock your framerate to either 60 or 120 FPS (ideally) and adjust your settings as needed to ensure your machine can retain that framerate throughout gameplay. And voila, that's it! In theory, anyway.
Hopefully, DF's advice combined with Arkane's hard behind-the-scenes work will satisfy some of Deathloop's. By most accounts, it is otherwise a fantastic game.