Dark Souls is infamous for the frame rate issues it had when it was launched on PS3 and Xbox 360. The game was tormented with frame drops during some sections, and it had frame pacing issues as the game progressed.
Players hoped that when the game will come to Xbox One Backwards Compatibility, it would improve the frame rates. This somehow happened, but the performance was still not improved as many hoped it would.
Releasing the game on Xbox One X has finally made it possible to play Dark Souls on a console with stable 30 fps, meaning that you do not have to have random frame rate drops to 20 fps on the Xbox One or Xbox 360.
YouTube Channel VGTech has made some analysis on the frame rate of the game, and the video below shows that the frame rate of 30fps stays throughout the bigger part of the time, even when during some certain sections the game drops to 15fps on the Xbox One and Xbox 360.
Even when the game had its big performance jump on Xbox One X, the Blight town still has frame rate drops on the Xbox One x, but the performance recovers more quickly. Xbox One X is available for purchase for $499.