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Network optimization for FPS games: the complete registry guide

#gaming #windows #networking #performance

Your in-game ping isn't just about your internet speed. The Windows network stack has multiple layers that add latency between the game server and what you see on screen. Here's what to change.

Nagle's Algorithm

This is the most impactful single change. Nagle's algorithm waits to accumulate small TCP packets before sending them — good for throughput, bad for real-time game data.

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
TCPNoDelay = 1
TcpAckFrequency = 1
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AFD (Ancillary Function Driver) buffers

AFD is the Windows socket layer. Its default send/receive windows are sized conservatively. For gaming:

HKLM\SYSTEM\CurrentControlSet\Services\AFD\Parameters
DefaultSendWindow = 65536
DefaultReceiveWindow = 65536
FastSendDatagramThreshold = 1024
FastCopyReceiveThreshold = 1024
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TCP receive window auto-tuning

Windows dynamically adjusts TCP window sizes based on connection quality. For low-latency game connections, fixed windows are more predictable:

netsh int tcp set global autotuninglevel=disabled
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Receive Segment Coalescing (RSC)

RSC batches incoming TCP segments to reduce CPU interrupts. For gaming, you want packets processed immediately:

netsh int tcp set global rsc=disabled
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NDIS packet tracking 

HKLM\SYSTEM\CurrentControlSet\Services\NDIS\Parameters
TrackNblOwner = 0
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Disables network buffer list owner tracking in the NDIS driver stack. Reduces per-packet overhead.

NIC-level changes

In Device Manager → your NIC → Advanced:

  • Interrupt Moderation: Disabled
  • Energy Efficient Ethernet: Disabled
  • Wake on Magic Packet: Disabled
  • Flow Control: Disabled

These can't be set via registry easily — they're per-adapter settings.

DNS cache 

HKLM\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters
NegativeCacheTime = 0
NetFailureCacheTime = 0
MaxNegativeCacheTtl = 0
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Eliminates negative DNS caching — no more "this server doesn't exist" being cached for 5 minutes after a failed lookup.

IzanagiOP's Scatter Pack and HitSync Pack cover all of this. It also has an MTU auto-detector that finds your real MTU via binary search. Discord: https://terweb.lt/

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