Performance massively drops when using Graphics API option: prefer openGL in 26.2
In 26.1.2 OpenGL gave me normal stable FPS but in 26.2 OpenGL had a massive FPS drop with sudden short FPS boosts, although Vulkan remained stable.
Tested with different video settings.
After further testing i saw that the problem occurred more on servers BUT especially when the mod “Iris” is installed. This problem can be linked to either minecraft or Iris so we need to wait and i will report this to Iris team also.
I think this is the last edit.
The Iris Team have made a new version fixing this problem so try downloading the latest version(mine is 1.11.1 fabric) so this case will be closed and have a good day.
Environment
GTX 1060 , i7-8750H, 32GB ddr4 , windows 11.
I'm having the exact same problem. Thanks to you, I figured out what was wrong with this version. Playing version 26.2, I had the same problems as you. Unstable frame drops that made the game run like crap. Initially, I thought it was a version-specific issue, since going back to version 26.1.2, these issues weren't there, but instead. I changed to Vulkan and the game now runs very smoothly. The only flaw is that I can't use shaders with iris and sodium if Vulkan is used. I hope they fix it.
And I tell you, it happened to me, even though I have these specs:
Rtx 2060.
I7 9700F.
32GB RAM
Windows 11 25H2.
And I have everything up to date.