They had to go that far to convince Jensen Huang’s company that the problem really was in its own driver.

During the most recent Path of Exile 2 league, there was a point when we thought we would have to stop playing. Roughly every 20 minutes, the entire game would freeze. We would wait 30 seconds for everything to start working again, praying that we would not lose our character the moment we regained control. Since the game’s Early Access release, players have experienced periodic freezes and crashes. The only solution was to change a setting that significantly degraded the graphical quality until developer Grinding Gear Games, or GGG, finally found a fix.

As it turned out, the freezes were only the beginning of the debugging saga that the developers had been dealing with for the past year and a half. This week marked the end of the battle against Path of Exile 2’s persistent GPU shader crashes, thanks to the enormous effort GGG invested in diagnosing the issue. Although the developers identified the exact piece of Nvidia driver code causing the problem, game director Jonathan Rogers explained in a recently released video that the graphics company would not fix anything unless it was provided with the steps required to reproduce the bug.

GGG initially had someone play the game for several hours in the hope that it would eventually crash. However, since there were no concrete clues about what might be causing the problem, this approach relied entirely on chance. After failing to find a solution, GGG decided to create a system that would at least prevent the game itself from crashing. The freezes occurred because the GPU crashed and the game, instead of shutting down, reloaded the textures, shaders, and the entire engine. According to Rogers, the workaround was good enough, but the team remained determined to discover the underlying cause. GGG built several features into the engine to track useful data, along with a special replay system capable of replaying lengthy gameplay sessions lasting several hours on the PCs in its office.

The team packaged the replay into a runnable file and then sent Nvidia the PC on which it worked. It took some time, but Nvidia eventually responded and said it would investigate the matter. A few weeks later, an update arrived: increasing the shader-heap size would eliminate the crashes entirely. Earlier this week, Nvidia released Game Ready Driver 610.88 with the following note: “Path of Exile 2: Fixed the occasional long pauses that could occur after extended gameplay sessions in DX12 mode.”

“Unfortunately, those steps can’t just be ‘grind through the highest-tier, heavily juiced maps.’ Even though this is ultimately a bug in the Nvidia driver that affected a huge number of high-level players, quite frankly, they just didn’t seem to believe that it was as common as we said it was. At that point, you’re just taking shots in the dark. So, we went down an incredibly deep rabbit hole trying to reproduce it. Eventually, with replays and an incredible amount of work from our engine team, we managed to reproduce it fairly consistently. We got a replay that would reproduce the bug every five to seven minutes on average. We sent Nvidia the PC, the monitor, and even the mouse and keyboard. The saga is over, and now our engine programmers can focus on optimizing more conventional performance problems,” Rogers said before popping open a bottle of champagne in celebration.

It took almost two years to resolve this issue. Hopefully, no further bugs will appear, allowing everyone to enjoy a seamless experience when the game reaches version 1.0 later this year.

Source: PC Gamer