So basically in 1.8 the was a 63 block update limit (as explained here)

My question is when the command blocks changed, does the server still send packets every tick telling the client that the command block were powered? If so is there anything I can do to remove that so I can have a large amount of command blocks near the person and not lag them out? Or in general should I not have my command blocks near the person?

And on a side note, can you also tell me what the block update limit (per chunk) was increased to?

1 Answer 1


The maximum number of updates-per-tick before sending the whole chunk has not changed.

As of 1.9+, command blocks do not save its powered state as a metadata value and is instead saved as NBT, so that part at least is no longer sent to the player. However, if the command block saves its last output, the client will be sent information.

You can disable last output per command block via the interface by clicking the "O" button next to the "Previous Output" textbox, which will prevent the player being sent that block update data:

Command block interface

If the sendCommandFeedback gamerule is set to false, last output will be disabled on new command blocks that you place.

Redstone blocks being created and replaced to create a /fill clock are still going to cause updates, so you should no longer use /fill clocks. Instead, use Repeating command blocks to act as a clock, and attach Chain command blocks to it for them to be activated. As long as output is disabled for all command blocks, you will not run into any block updates being sent to the player.

  • 1
    I don't use fill clocks anymore. I was just refering to 1.8 and their fill clocks as that was the only information I could find. Also thanks, you gave me the exact information I was looking for.
    – LethaIity
    Jun 24, 2016 at 18:00

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