I've watched tutorial videos, and it worked before, but now it doesn't work and gives me a new default JVM argument, -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M rather than what it used to say. How can I make it so that I've allocated 4GB to MC? I've tried changing the first part, -Xmx1G, to -Xmx4G, but it didn't work.
-Xmx4G. Do you have over 4gigs of ram? You do NOT want to allocate 4gigs of ram if you only have 4. Also, RAM is a common noob mistake. Now while Java is a RAM eater, having a bad G-card or CPU would also slow down your game
That it didn't but your new 'old' way works makes me guess that you have Razer Synapse on your computer.