Callisto Protocol's PC patch tested: shader compilation stutter fixed, but issues remain

Callisto Protocol launched to a mixed reception - the game itself was recommended by Eurogamer - but only the Xbox and PC versions of the game debuted with fairly severe technical issues, with the PC version being the worst of all thanks to severe shader compilation stutter even on extremely powerful machines. With patches to fix these issues now available, the most recent of which was deployed on 7th December, we went back into the game to assess the situation - was shader compilation fixed? And do other issues still persist?

Firstly, yes - nearly all shader compilation stutter that we experienced in the first 30 minutes of the game has now been eliminated. We can't guarantee that all shader compilation stutters are gone beyond this, but we would at least expect this to be the case! This fix makes the game much more enjoyable, as dramatic tension isn't broken by severe hitching when new objects or effects appear, but things aren't quite perfect yet.

The stutter has been fixed by a lengthy shader precompilation step in the game menu, but this unfortunately proceeds without any visual indicator to judge its progress. While precompilation is occurring, the game's frame-rate is understandably low, which makes the menu quite unresponsive. Ideally, an indicator of some sort would be added to the main menu so you can see how much progress has been made, or at least that shader compilation is still ongoing - then you could leave it on the menu and do something else for a few minutes, then come back and know it was complete.

There are still some stutters in the game, but these now appear to be related to loading, like similar stutters exhibited in the PS5, Xbox Series X and Series S versions as John highlighted in his video on the subject.

While this is still solid progress, more issues in the PC version do remain. CPU utilisation remains quite single-threaded, so we still see the odd situation of both CPU and GPU utilisation being rather low and frame-rates being surprisingly low in many scenarios. This is true even on one of the fastest gaming CPUs, the Core i9 12900K, backed with extremely fast DDR5-6400 RAM, where the game still dips below 60fps at points when paired with an RTX 4090. Clearly, more optimisation would be welcomed, although it's impossible to say whether this will be forthcoming as it depends on how the game has been architected at a rather basic level.

So overall then, this is a positive development and we're glad to see Striking Distance Studios take steps to improve the PC version, even if not all issues have yet been solved.