It's responsive and fast for you in a single fullscreen 2560x1600 term while catting a large file in a split? Performance is a lot more reasonable if you're us

It's responsive and fast for you in a single fullscreen 2560x1600 term while catting a large file in a split? Performance is a lot more reasonable if you're using more traditionally-sized terms and let Terminator manage the splitting. Perhaps it's depending on some hardware acceleration feature not provided by VirtualBox.