Barteks2x
commented
4 years ago Note: I'm not optifine developer, and it's not my choice whether openj9 will be supported or not. Optifine developer may still choose to support it. I'm just pointing out what I know.
OpenJ9 isn't really well supported in MC in general. Forge 1.12.2 has some issues with it that probably won't be fixed, and 1.13+ forge doesn't even run (and won't get fixed)
OpenJ9 also doesn't have better performance, and memory saving are minimal, it's just that openjdk isn't by default configured to conserve memory.
Want very similar memory usage with hotspot? It can be configured in similar way. No, this don't scale well to modpacks. And performance is likely to be worse than with default settings. But this is essentially what openj9 is doing by default (openj9 behavior can't be replicated exactly because some features required can't be combined together on hotspot, and some don't exist)
-Xms8M
-Xmx2G
-Xss256k
-Xmn64M
-XX:+NeverTenure
-XX:NewRatio=3
-XX:+UseParallelOldGC
-XX:MinHeapFreeRatio=5
-XX:MaxHeapFreeRatio=15
-XX:+UseCodeCacheFlushing
-XX:+CMSClassUnloadingEnabled
I tried to run optifine 1.12.2 F5 with Eclipse OpenJ9 VM (can download at https://adoptopenjdk.net/releases.html?variant=openjdk8&jvmVariant=openj9), but it doesn't run, and crashed. I want to run this with openj9 for low RAM use and better performance, so I hope these problems are solved.