If you have a performance, it’s best to make a .nps file that you can send to the developers so that they can investigate further.

Installing Sampler

Sampler is a mod by Player that generates .nps files. You can download it from here.

For Minecraft 1.12

http://files.player.to/sampler-1.73.jar

For Minecraft 1.11

http://files.player.to/sampler-1.72.1.jar

For Minecraft 1.10

http://files.player.to/sampler-1.69.3.jar

Running Sampler

Then you can /sampler start and /sampler stop while it’s lagging.

Then a simple /sampler export [name of exported nps file here] will write out the .nps file that can be read by the developers in VisualVM.

Where to run Sampler?

  • Is it a performance on the server, like tick lag? Run Sampler on the server, NOT on your client!

  • Is it a performance on the client, like FPS lag? Run Sampler on the client, NOT on your server!