I am not sure if this is only my machine, but when I have the GUI editor open, the GPU jacks up to max. I realized this when I was trying to test my mods and my machine was super laggy. Seems a bit much for such simple graphics, feels like a bug to me. I see that don't have much RAM left, but the CPU stays roughly at 50%.
MCreator issue tracker has been migrated to GitHub.
Existing tickets have been migrated to GitHub. Please open new tickets on the GitHub tracker instead. If you do not have a GitHub account, all feature requests and bug reports from forums are still considered and checked by the maintainers.