Network stack
NetworkThrottlingIndex
The multimedia network throttle, when it applies, and when it is irrelevant
Last updated
What is NetworkThrottlingIndex and should you disable it?
NetworkThrottlingIndex limits how many network packets per millisecond Windows will process for non-multimedia traffic while a multimedia application is running. It exists so that heavy network activity cannot cause audio or video to skip. The default is 10 packets per millisecond. Setting it to 0xFFFFFFFF removes the limit, which is one of the few tweaks in this category with a clear, documented mechanism -- but it only ever applies while an MMCSS multimedia task is active.
Registry location and values
NetworkThrottlingIndex
- Location
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile- Value name
NetworkThrottlingIndex- Type
REG_DWORD- Default
- 10 (0x0A)
| Value | What it does |
|---|---|
10 | Default. Processes up to 10 packets per millisecond for non-multimedia traffic while multimedia is active. |
0xFFFFFFFF (4294967295) | Disables throttling entirely. The documented way to turn the feature off. |
Other values | Interpreted as the packets-per-millisecond ceiling. |
What Windows actually does with this
When a process registers with MMCSS for a multimedia task, the network stack applies a rate limit to packet indications for traffic not associated with that task. The intent is that a large download cannot cause a video call to stutter. Outside of an active multimedia task, the throttle is not applied at all.
What it affects
Throughput of background network traffic during multimedia playback. On a gigabit connection the 10-packets-per-millisecond ceiling can measurably cap throughput, which is why the tweak became well known among people doing large transfers while playing audio.
Is it worth changing?
Real, documented, and genuinely worth disabling on a machine used for high-throughput networking. As a latency or ping tweak for gaming it is oversold: it caps throughput, not latency, and it only engages while an MMCSS multimedia task is running. If your complaint is ping or jitter rather than transfer speed, this is not your problem.
What can go wrong
Low. The feature exists to protect audio and video smoothness, so disabling it can in principle allow heavy network traffic to interfere with playback. In practice, on modern hardware, rarely noticeable.
How to undo it
Set the value back to 10 (decimal) and restart, or delete the value and let Windows recreate it.
Create a System Restore Point before editing the registry. Every setting on this page is reversible, but a restore point is the difference between undoing one change and reinstalling Windows.
Which Windows versions this applies to
Windows Vista and later.
NetworkThrottlingIndex: common questions
Will this lower my ping?
No. It governs how many packets per millisecond are processed for background traffic during multimedia playback. Ping is round-trip time to a server, which is dominated by distance and routing.
Is 0xFFFFFFFF safe?
It is the documented way to disable the feature, not a hack. The only trade-off is the one the feature was protecting against.
Sources
Does JINSHI Tweaks change this?
This page documents a setting that corresponds to the following toggle in JINSHI PC Tweaks: Disable Network Throttling.
The reference above is written to be usable without the product. Everything here can be applied by hand for free. What the application adds is that the change is applied in one pass, a System Restore Point is created first, and each toggle can be reversed individually.