A recently released update for the Xbox One Call Of Duty: Ghosts has reportedly introduced performance issues that weren't previously in the game.
The update was designed to prepare the game for the Onslaught DLC, as well as adding bug fixes, new features and balance tweaks to the game's multiplayer modes.
However, early reports on NeoGAF from players who had downloaded the update suggested the game was performing poorer than before the update.
In particular, the Stonehaven stage was singled out as a major offender, with explosions and other effects affecting the game's frame rate.
Eurogamer's Digital Foundry has since run a detailed test of the game post-update, and its findings suggest the update has indeed had a negative impact on its performance.
"While the game does indeed hit 60fps in [the Stonehaven] stage, frame-rates are dramatically impacted when the whole level is in view, with metrics varying between 46-60fps as we run across the landscape," the site claims.
"As frame-rates fall below the desired 60fps target, we also see the appearance of some screen-tear, adding some judder, making drops in smoothness more noticeable."
"Meanwhile, aiming down the barrel of a sniper scope can see significant drops down as far as the mid-30s - something we never encountered before in ether next-gen version of Ghosts during multiplayer.
"As a result of the fluctuating frame-rate we can feel a clear reduction in the responsiveness of the controls, while on a visual level the introduction of stutter impacts the smooth flow traditionally associated with Call of Duty multiplayer action."
It's stressed that performance drops are far less severe on other stages, and that the PS4 version remains the same as it was at launch: "not as smooth as Xbox One, but with a much higher rendering resolution."