-Xmx4G -Xms2G -d64 -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:MaxGCPauseMillis=80 -XX:+UseStringDeduplication -XX:+UseCompressedOops -XX:+UseCodeCacheFlushing -XX

arallelGCThreads=4
Certain parameters might differ for your PC.
- Xmx (maximum) and Xms (starting/minimum) is the memory allocation. Do not allocate all your memory, leave something for your OS. In most cases 4G is enough. If your world is more progressed you might want to raise the Xmx
- XX ParallelGCThreads=4 (4 = number of your CPU cores)