the same thing happens with:
- different shaders (sometimes I get up to 30 more fps on optifine than I do on iris)
- different versions
- different worlds
- different number of other performance mods (or none)
- different cpus (this has happened so far on both my old i5 9600k and my current r7 5700x. gpu is a 3070 with the latest 560.70 drivers)
- different nvidia drivers
- different windows installs
I've used almost the exact same settings on both iris and optifine, and I say almost because optifine and sodium have very different settings options