Improving Gaming Latency by Disabling Nagle’s Algorithm

Latency, or “ping,” is the delay between a player’s action and the server’s response. In online gaming, lower latency results in smoother gameplay and faster reaction times, which are crucial for competitive PVP. Especially in games like Minecraft PVP, where competitive fights are mainly based on players’ knockback they give and take. This knockback is directly related to the latency between the player and the server.

One way to reduce latency is by disabling Nagle’s algorithm, a TCP/IP feature designed to optimize network traffic by reducing the number of packets sent over the network. Nagle’s algorithm combines multiple small packets into a single, larger packet to increase efficiency. However, this can introduce delays in real-time applications.

Nagle’s Algorithm

if there is new data to send then
  if the window size ≥ MSS and available data is ≥ MSS then
    send complete MSS segment now
  else
    if there is unconfirmed data still in the pipe then
      enqueue data in the buffer until an acknowledge is received
    else
      send data immediately
    end if
  end if
end if

This algorithm is enabled by default in Windows, but it can be disabled by modifying the Windows registry

How Windows Registry Changes Improve Latency

The blog post describes modifications to the Windows registry to improve how TCP (Transmission Control Protocol) packets are handled. TCP is a core protocol of the Internet Protocol (IP) suite and is used for reliable data transmission. By default, TCP is optimized for data integrity rather than speed, which can introduce latency in real-time applications like gaming.

WARNING : DO NOT ATTEMPT TO DO THIS IF YOU ARE NOT OKAY WITH EDITING REGISTRY VALUES. YOU CAN CAUSE SEVERE DAMAGE TO YOUR WINDOWS SETUP IF YOU MESS UP!!

Key Registry Modifications

1. TcpAckFrequency
   • Default Behavior: TCP uses a mechanism called “delayed ACK” where it waits before acknowledging the receipt of packets. This can introduce a delay.
   • Modification: Setting TcpAckFrequency to 1 disables delayed ACK, making the system acknowledge packets immediately.
   • Effect: Reduces the delay in packet acknowledgment, thereby decreasing latency.
2. TCPNoDelay
   • Default Behavior: TCP implements the Nagle algorithm to combine a number of small outgoing messages and send them all at once. This reduces the number of packets sent but can introduce delays.
   • Modification: Setting TCPNoDelay to 1 disables the Nagle algorithm.
   • Effect: Ensures packets are sent immediately without delay, reducing latency.

Steps to Implement the Changes

1. Open the Windows Registry Editor
   • Access the registry editor by typing regedit in the Run dialog (Windows Key + R).
2. Navigate to the TCP Parameters
   • Locate the path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces.
3. Modify Each Network Interface
   • For each subfolder under “Interfaces”:
     • Create or verify the existence of TcpAckFrequency and TCPNoDelay DWORD keys.
     • Set their values to 1 (hexadecimal).
4. Restart the Computer
   • Changes will take effect after a system restart.

Impact on Minecraft PVP

Practical Effects

• Reduced Latency: By acknowledging packets immediately and sending them without delay, the modifications significantly reduce the time it takes for data to travel between your computer and the game server.
• Smoother Gameplay: This results in more responsive controls and quicker reactions, which are critical in competitive PVP scenarios.

Limitations and Considerations

• CPU Usage: These changes might slightly increase CPU load, but most CPUs can handle this without significant issues.
• Internet Speed: While this method optimizes packet handling, it does not increase your internet speed. A stable and sufficiently fast internet connection is still necessary.
• Technical Expertise: Modifying the registry carries risks. Incorrect changes can cause system instability. Only users confident in their technical skills should attempt this.

Pierre.