Competitive gaming network optimization issues

[notr1ch]

I noticed the following network tweaks were added when using the competitive gaming option:

REM Disable Nagle Algorithm (reduces input lag)
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces" /v TcpAckFrequency /t REG_DWORD /d 1 /f
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces" /v TCPNoDelay /t REG_DWORD /d 1 /f

The first key turns off delayed acks, however, this is a per interface setting - putting it in the Interfaces key itself won't do anything, it must be under the interface GUID (see https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/registry-entry-control-tcp-acknowledgment-behavior). Further, this setting is only really useful in situations where a TCP-based game is still using Nagle's algorithm, where the two interact poorly - Nagle wants to delay sending until it receives an ack, and delayed ack is delaying that ack (https://brooker.co.za/blog/2024/05/09/nagle.html). However, the few games still using TCP (typically MMOs) correctly set TCP_NODELAY these days, so trading off the potential of a game misusing TCP for higher ack overhead for all TCP connections on the system is debatable these days.

The second key is snake oil - there is no global way to turn off Nagle's algorithm in Windows, it must be done per application via socket options. This recommendation has been passed around for years under various keys, stemming from a misunderstanding of the Microsoft Message Queue service which does have a registry entry to disable its own use of Nagle's algorithm (https://support.microsoft.com/en-us/topic/fix-tcp-ip-nagle-algorithm-for-microsoft-message-queue-server-can-be-disabled-74ba2f6a-e558-d1df-1c60-57b0fab68ccc), but that has no impact outside of the MSMQ service.

[kaic]

Thanks for the detailed explanation, great points we have in there 👍

You’re right on both counts. The delayed ACK tweak is per-interface and, even when applied correctly, has very limited impact today since most modern games use UDP or already handle this properly.

And agreed on TcpNoDelay via registry - that one’s basically snake oil. There’s no supported way to disable Nagle globally in Windows, and the misconception about the MSMQ registry key has persisted for way too long.

Given the trade-offs and questionable benefits, I’ll be updating the Competitive Gaming profile to:

• Remove the TcpNoDelay registry tweak.
• Either remove TcpAckFrequency or keep it as an advanced/opt-in option with clearer context.
• Add a short note in the docs explaining why these tweaks are mostly legacy advice.
• Or remove this option from the catalog.

Really appreciate you calling this out, feedback like this helps keep the tool practical and honest.

[kaic]

Merged this fix in PR #24 . I removed the “disable Nagle”/TCPNoDelay registry tweak (it’s not a real global toggle) and removed TcpAckFrequency from the default competitive profile, since it was being misapplied. If someone still wants to try it, I added an “Advanced” option that correctly applies TcpAckFrequency=1 per active interface and includes a warning that it may not help (TCP-only, can increase ACK traffic). Thanks again for the detailed report.