What is network “Interrupt Moderation” that might be reducing your FPS in online games?

If you've ever noticed that your connection runs "smoothly" in speed tests, but in online games, video calls, or real-time applications everything seems to respond with a slight delay, the key may very well lie in a function of your network card called Interrupt ModerationIt's a setting that almost always goes unnoticed, it comes enabled by default on many adapters, and yet it can significantly change the feeling of smoothness.

This feature is not black magic or a hidden trick to gain FPS, but a technical mechanism for balancing. network performance, CPU usage, and latencyUnderstanding what it does, when to activate it, when it might be better to deactivate it, and how to configure it in Windows and Linux will help you get the most out of your connection, especially if you play online games or work with applications that are very sensitive to latency.

What is Interrupt Moderation and why does it exist?

On a computer, a interruption is a signal This forces the CPU to interrupt its current task to handle something more urgent, such as the arrival of a network packet. Each time the network interface card (NIC) receives data, it can notify the processor via an interrupt so that the operating system and driver can manage those packets.

The problem arises when the network speed is high or many small packets are being handled: the NIC can generate thousands of interruptions per secondconstantly interrupting the CPU and harming overall system performance. To avoid this interrupt "bombardment" effect, many adapters incorporate what is called moderation of interruptions.

With Interrupt Moderation enabled, the network card does not generate an interrupt as soon as each packet arrives, but instead Wait until you have accumulated several packages or until a certain time has passed. before notifying the CPU. In this way, a single interrupt event can process multiple packets at once, significantly reducing the load on the processor.

This behavior introduces a kind of "waiting queue": the NIC hardware briefly let the packets rest in an internal buffer And only when a condition is met (number of packets or maximum waiting time) does it trigger the interrupt. The exact algorithm, thresholds, and timings are usually defined by the hardware vendor and can vary between manufacturers and models.

Impact on latency and bandwidth: the delicate balance

Moderating interruptions always involves a compromise between latency and aggregate performanceBy slightly delaying the moment the CPU processes each packet, the number of interrupts is reduced and resource usage is improved, but a small extra delay is added to the delivery of data to applications.

The round-trip time (RTT) of a package is one of the most common measures for estimating the effective bandwidth and connection status between two points. When Interrupt Moderation is enabled, the RTT perceived by applications may be slightly longer than the actual time it takes for the packet to travel across the network, because once it reaches the network card, it may spend a few milliseconds "queuing" before the operating system processes it.

This means that, although from the perspective of the physical network the packet arrived quickly, the The app sees it later due to that small internal delay. In many scenarios (large file transfers, streaming, web browsing) this increase in latency is irrelevant compared to the overall performance improvement and reduced CPU usage.

However, in applications that are ultra-sensitive to latency, such as competitive online games or certain real-time communicationsThose extra milliseconds can be noticed as less responsive controls or feelings of delay when interacting, even when the ping and bandwidth are, in theory, correct.

Interrupt moderation in NDIS (Windows) and driver support

In modern Windows environments, network drivers are based on the NDIS architecture. Starting with NDIS 6.0, all miniport controllers (the drivers that communicate directly with the network card) must support the OID identifier called OID_GEN_INTERRUPT_MODERATION, which is used to manage this functionality.

This OID allows the operating system or diagnostic applications to request the driver to dynamically enable or disable interruption moderationor check their current status. This allows, for example, highly accurate latency measurement tools to temporarily disable moderation to obtain round-trip times that are closer to reality.

If a miniport controller does not implement interrupt moderation, it must explicitly state this. NdisInterruptModerationNotSupported in the field InterruptModeration of the structure NDIS_INTERRUPT_MODERATION_PARAMETERSIn other words, the driver declares that this function does not exist for that hardware.

When the card and driver do support it, Microsoft's recommendation is that come enabled by default, except that a standard Registry keyword, also called InterruptModerationI disabled it. This way, most users benefit from better overall performance without having to change anything, and only those who need to fine-tune latency need to change this behavior.

How it affects online games and real-time applications

In the real world, many users discover the existence of Interrupt Moderation by investigating why their The online game is acting "weird" Despite having a good connection and a relatively powerful PC, the typical case is someone who sees good bandwidth in tests, a decent ping on servers, but still notices micro-latencies when shooting, moving, or interacting with the game environment.

Several players have commented, for example, on their experience with demanding titles like Star Citizen: even if they already had other performance adjustments applied (graphics settings, game options, system cleanup), they continued to experience network lag and some control delay. Upon checking the properties of the Windows network adapter, they found the option Interrupt Moderation and they decided to deactivate it.

The practical explanation is that, with moderation enabled, the network card acts as a kind of "lazy postman"Instead of delivering each packet instantly, it waits until it has several packets so that the "trip" to the CPU is worthwhile. When traffic is very irregular or there are bursts of small packets, this can result in slightly delayed delivery of game updates.

By disabling this function, the NIC switches to interrupt the CPU for almost every packetThis theoretically minimizes latency at the cost of increasing the processor's workload. On many modern systems with powerful CPUs and plenty of cores, this increased CPU usage is usually manageable, and some gamers report more responsive controls and a smoother feel, even if the FPS remains unchanged.

It is important to clarify that this It doesn't solve the game server problemsIf the company's server (for example, CIG in Star Citizen) is overloaded, has bugs, or is poorly managing traffic, you'll still see lag or stuttering because the problem lies on the other end. All you're doing is reducing the latency added by your network card and its driver on your end.

Interrupt Moderation Rate and Interrupt Throttle Rate (ITR)

Some manufacturers, such as Intel, offer an extra level of tuning called Interrupt Moderation Ratewhich in practice controls the Interrupt Throttle Rate (ITR)This parameter defines the maximum frequency at which transmission and reception interruptions are allowed.

When an event occurs (for example, receiving packets), the adapter generates an interrupt. Each interrupt causes the CPU Please temporarily stop the application which is running to support the network driver. At high link speeds or with heavy traffic, this effect is amplified and can significantly degrade system performance.

Increasing the ITR value reduces the interrupt frequency, allowing the CPU to work more efficiently and achieving improved overall performance in high-traffic tasksThe price is that the driver takes a little longer to react to new packets, which translates into an increase in latency in handling that data.

If the card is receiving many small packets, it may be advisable to lower the moderation rate (a lower ITR) so that the driver is faster processing of each packetIf, on the other hand, large and continuous data flows are being handled (such as copies of huge files over the network), more aggressive moderation can be beneficial.

In Intel PROSet and its utilities, it is possible to find profiles such as Adaptive, Extreme, High, Medium, Low, Minimal and OffAdaptive mode is usually the recommended default because it attempts to automatically balance CPU load and latency, but in specific scenarios it may be interesting to try lower values ​​or even Off to have minimal latency.

How to change Interrupt Moderation in Windows

In Windows, most adapters allow you to configure Interrupt Moderation from within the adapter itself. Device Manager or from the manufacturer's tools. The generic path, valid for many drivers, is as follows:

First, open the Control Panel. You can press Press Windows + R and type "control panel" In the Run dialog box, type "network" and press Enter. In the Control Panel search bar, type "network" and open it. Networking and sharing centerThere, click on Change adapter settings to view your network interfaces.

Regarding the adapter you are using (for example, your Realtek PCIe GBE Ethernet card or an Intel adapter), right click and select PropertiesIn the window that appears, press the button Set up…In the new window, go to the tab Advanced, where you will see a list of adapter properties.

In that list you should find an entry called Interrupt Moderation or "Moderating Interruptions"If it appears, you can change its value to Disabled to force the NIC to generate interrupts more frequently. Apply the changes and close the windows. In many cases, a system restart is not required for the new setting to take effect.

Some manufacturers, such as Intel, also allow you to control this parameter from Intel PROSet Adapter Configuration Utility or via PowerShell. For example, the cmdlet:

Set-IntelNetAdapterSetting -Name "<adapter_name>" -DisplayName "Interrupt Moderation Rate" -DisplayValue "Adaptive"

This is used to set the Adaptive mode for the interrupt moderation rate. To use values ​​like High, Medium, Low, Minimal, Off, etc., simply replace "Adaptive" for the desired profileprovided the card model supports it.

Network card settings that affect stability

In addition to Interrupt Moderation, there are several advanced network driver options that can affect online games, streaming and callsAmong the most relevant are:

Options such as “Energy Efficient Ethernet” or “Green Ethernet” They attempt to reduce energy consumption by turning off or reducing link activity when there isn't much traffic. Although in theory they shouldn't cause problems, in practice some users report micro-outages, packet loss, or brief freezes when using these features with certain routers or switches.

The parameters “Large Send Offload (LSO)” for IPv4 and IPv6 They allow the card to group large blocks of data and fragment them in hardware, relieving the CPU. However, in networks with older hardware, unusual firewalls, or problematic drivers, these features can introduce anomalies, forwarding, or unpredictable behavior in real-time traffic.

As a general recommendation, if you're experiencing stability issues in games or video calls, it may be helpful to go to the advanced properties of your adapter and temporarily disable:

• Interrupt Moderation
• Energy Efficient Ethernet
• Large Send Offload (IPv4/IPv6)
• Green Ethernet or similar savings options

After applying these changes, restart your computer if necessary and check if the feel in games and real-time applications improvesIf you don't see a difference, or if you notice increased CPU usage without clear benefits, you can always restore the previous settings.

Configuring interrupt moderation in Linux (ethtool)

In Linux systems, the usual tool for adjusting the behavior of network cards at a low level is ethtoolThrough it, you can modify, among other things, the interrupt coalescence parameters of a specific interface.

A simple example would be enabling the adaptive receive coalescence mode with:

ethtool -C adaptive-rx on

where would be the interface name (for example, eth0 o enp3s0). From there, ethtool also allows you to adjust times in microseconds, number of packets, etc., to fine-tune the point at which the NIC triggers interrupts to the CPU.

These settings in Linux follow the same logic as in Windows: More coalescence means fewer interruptions and better CPU utilizationHowever, there is a greater delay in the delivery of each packet. Less coalescence means minimal latency, at the cost of a higher load on the system when traffic is heavy.

Diagnosing network problems before touching Interrupt Moderation

Before you drive yourself crazy changing advanced adapter settings, it's worth checking if the problem you're having actually comes from the card or configuration y Identifying problems with PerfMonor if the source is your ISP, your router, or even the game server itself.

A useful first step is to test the connection using a mobile hotspot From your phone. Connect your PC to the mobile network and repeat the tests (online gaming, video calls, etc.). If everything suddenly works fine, the problem clearly points to your phone. Internet provider or your local infrastructure (router, ONT, cabling).

Then it's interesting to use measurement tools such as the test of Measurement Lab (NDT), available in their official websiteRun the test before and after changing settings such as Interrupt Moderation and take screenshots of the results: bandwidth, latency, advanced details.

During these tests, pay attention to parameters such as:

• Duplex discrepancies (half/full duplex poorly negotiated)
• Cable failures or errors (physical errors, signal loss)
• Congestion or bottlenecks persistent
• Duplicate ACKs or other symptoms of TCP stack problems

If you find any of these signs, it's best to address those causes first, because they are fundamental network problems that are not resolved by simply moderating interruptions.

Another very revealing test for games is to measure the latency within your own local networkOn Windows, while playing or reproducing the glitch, open a command prompt (cmd) and run:

ping -n 100 192.168.1.1

replacing 192.168.1.1 for the IP of your routerIf you notice your ping jumping from 1-2 ms to peaks of 50-100 ms or more, you're likely experiencing Wi-Fi interference, LAN congestion, or a poor router. This will affect all traffic, including game packets.

In short, Interrupt Moderation, interrupt coalescence, and parameters like Interrupt Throttle Rate are mechanisms designed to reduce CPU load and improve overall network performance, but at the cost of adding some latency. For most common uses, the default setting is more than sufficient, but if you work with latency-sensitive online games, real-time traffic, or need very precise round-trip time measurements, it's worth exploring and testing these settings, always after first ruling out basic network, router, or provider problems that won't be fixed simply by tweaking adapter options.

Related article:

Is your PC running slow? Learn how to identify the problem with Perfmon in Windows.

Daniel Terrasa

Editor specialized in technology and internet issues with more than ten years of experience in different digital media. I have worked as an editor and content creator for e-commerce, communication, online marketing and advertising companies. I have also written on economics, finance and other sectors websites. My work is also my passion. Now, through my articles in Tecnobits, I try to explore all the news and new opportunities that the world of technology offers us every day to improve our lives.