If your using a Nvidia card you can go through this process:
1. Open up the Nvidia Control Panel
2. Select "Manage 3d Settings" on list on the left
3. Select the "Program Settings"
4. From the first drop down list select "c:\ [some file order] \javaw.exe"
5. Press the "Add" button
6. From the second drop down list select "High-performance NVIDIA processor"
7. Make sure the two drop down lists are correct, then press "Apply"
Now any program or game that uses java should use your Nvidia processor instead of integrated graphics, and for me it has improved my fps in Minecraft and Starmade MASSIVELY. I can land on a 500 diameter planet and have a solid 60 fps, and I'm just on a decent gaming laptop.
I'm not sure how to do this for AMD cards, but I think the procedure is kind of similar.
This process obviously isn't well known, so that's why I think there should be some in-game prompt.