Storport.sys is a system-supplied storage port driver, such as NVMe over fibre channel (FC) or FC buses and RAID adapters. Issues can often be resolved by running the System File Checker as described here.

Advanced Configuration and Power Interface, or ACPI.sys, handles the computer’s power management, which controls different power modes, such as turning the power on from sleep mode when a peripheral, such as a mouse, is moved, when to operate the hard drive once connected, and conserving energy once the battery gets low.

First, disable any sleep settings on your PC and optimize the power settings using the steps in the linked article. In some cases, disabling the ACPI battery from within Device Manager also helps. That being said, it may disable the ability of the PC to charge the battery on a laptop.

USBPORT.sys is linked to your motherboard. Downloading the latest chipset drivers for your motherboard can often fix the problem. These drivers should be available from your computer or motherboard manufacturer’s support website. 

Transmission Control Protocol/Internet Protocol, or TCP/IP.sys, handles communication between computers. If TCP/IP.sys becomes corrupt, it will often result in stuttering audio and blue/black screens of death. The most common fix will require you to run Command Prompt as Administrator. 

1. Click the Windows icon, type “cmd”, then right-click Command Prompt and select Run as Administrator.
2. Type “netsh winsock reset”, then press Enter.
3. Type “netsh int ip reset”, then press Enter.
4. Type “ipconfig /release”, then press Enter.
5. Type “ipconfig /renew”, then press Enter.
6. Type “ipconfig /flushdns”, then press Enter.
7. Reboot your computer.

Network Driver Interface Specification, or ndis.sys, is a critical component of Windows; it’s the component and settings for Windows network settings. This file helps networked computers, as well as any connected device or hardware. If there’s latency caused by ndis.sys, or if it becomes corrupt, it often results in audio artefacts, decreased system performance, and even blue/black screens of death.

One last thing to check is your BIOS. Disable any unnecessary devices in your BIOS, including Legacy Drive A options, Serial Port and Parallel Port options, as well as Onboard Audio. If you’re still having problems, then consider disabling any stepping technologies like Intel SpeedStep (EIST)or AMD K8 Cool’n’Quiet.

• Disabling Intel SpeedStep or AMD’s Cool’n’Quiet can result in your CPU running at max clock. If you’re on a laptop, this also means that you will see degraded battery life.

Install or update the relevant drivers and BIOS for your motherboard, CPU, GPU and other components. To do this, you will need to know the manufacturer and model of the computer or its components, and then download the relevant drivers and BIOS from their website or using their applications.

We have seen that systems running a BIOS that predates the operating system (e.g., a BIOS version that predates Windows 11) can cause issues. It's particularly important that you update the BIOS if this is the case with your system.

If you are unsure of the make and model of any components, these can often be found in the manufacturer's applications that will probably be installed on your PC (e.g. NVIDIA Geforce Experience, AMD Software: Adrenalin Edition, ROG Armoury Crate, Gigabyte App Center etc.). These apps may be able to update the drivers for you. You can also find many of your Components in System Information:

Manufacturers may provide versions of their drivers designed for stability in professional applications, such as music, audio and video production. For example, AMD and NVIDIA provide a PRO and Studio version of their GPU drivers, respectively, and these may be more stable.

Disable ‘C-states’ in the BIOS

To save energy when the CPU is idle, the CPU can be commanded to enter a low-power mode. Different processors have varying arrays of power modes collectively called ‘C-states’ or ‘C-modes’. Different processors support different numbers of C-states — some don't support C-states at all.

We've found that having C-states enabled can cause adverse performance on some systems. If you're having audio performance issues, we recommend preventing your processor from entering power-saving C-states.

To do this, you will typically need to boot into the BIOS (Basic Input/Output System) of your computer. Please contact the manufacturer of your motherboard if you're not comfortable doing this. Focusrite Technical Support cannot help you tweak BIOS settings, because the BIOS layout and the available options differ greatly from one machine to another.

IRQs (interrupt requests) are used for operations such as mouse clicks or keystrokes. Any time you perform a task, like pressing a key on a MIDI keyboard, it tells the processor to stop what it’s doing in order to register the operation requested. Each of these operations communicates via a channel. An IRQ conflict means that two pieces of hardware are trying to communicate over the same channel. To check for IRQ conflicts:

• Launch Device Manager, click View, then select Resources by type.
• Expand Interrupt request (IRQ), then scroll down to the PCI section of the window.
  • Conflicts will be identified by an exclamation mark inside a yellow circle.
• Right-click one of the devices, then click the Resources tab.
• If the Change Settings box isn’t greyed out, select a new IRQ number, then click OK.
  • If the Change Settings box is greyed out, then you must update your hardware and OS drivers.

If you are still experiencing DPC latency after going through the checks in this article, please contact our Technical Support team, as they might be able to assist further - Technical Support Contact Details

Please bear in mind that our technical support engineers are not Windows or Microsoft technicians, and we'd also recommend contacting your PC and/or your motherboard manufacturer or a Windows technician for further advice if your issues persist.