Minecraft low gpu usage?

I have gtx 1060 3gb and when i tested minecraft it was only getting 400fps due to low gpu usage, even in skyblock gpu usage is 40-60 with fps 1000-3000. I know it's way too much fps but i just want to see the limit

It's probably waiting for the CPU, since Minecraft is light on the GPU to begin with and it isn't multi-threaded so it only uses one core of your CPU.

To really see the max frames per second you'd need a CPU with faster cores.