512x Uses ALL of My RAM

[Zianious]

I've got 32GB of RAM installed in my computer, and no matter how much I allocate, Minecraft ALWAYS uses all of my RAM to the point of the rest of my computer crashing.

Admittedly, I don't have this issue with 256x (I still only have around 15FPS though, the utilisation issue I've got with 512x plays a part in this), and there are more pressing issues that cause me to not use 512x (absolutely no utilisation of my CPU/GPU meaning less than 10 FPS), but with this issue of having not enough RAM (apparently), I cannot troubleshoot it properly.

Answers to several asked question:
- What are your specs? - i7 7700k, GTX 1080, 32GB 3200Mhz RAM, Game installed on a NVMe, Monitor is 2560x1080.
- Java arguments? - Untouched other than allocating 8GB RAM
- Mods, it's got to be your mods. Sounds like you have them ALL installed yeah? - Zero other than Sphax resource pack and Optifine with Sildur shaders (medium), and yes, this happens with no optifine used.
- How much RAM is used with 256x? - Allocated, 8GB, actual via task manager, 20GB used.

[HanFox]

That's just how Java works.

The xmx switch is just saying how much "heap" space the JVM can use, but Java itself can (and obviously will) use more for other stuff.

The FPS drops you experience are common on Nvidia cards now. Sometimes updating the drivers fixes it, but it's slowly becoming common knowledge Nvidia's FPS just isn't great in Minecraft...

You can search Google for other Java arguments you can try, which may reign in the memory usage, and you can try fiddling with graphical settings, but no two installations are the same, so mileage may vary.