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Show devices by their IRQ & how to avoid IRQ sharing in Windows

Show devices by their IRQ

To show devices by IRQ in Windows XP, Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2012 and Windows Server 2016, do the following:

  1. Launch Device Manger (in Windows Run or Search type devmgmt.msc or right click on Computer->select Manage->select Device Manager)
  2. In the menu select View -> Resources by connection
  3. Expand Interrupt by request (IRQ) item category and scroll down to items starting with (PCI)

Additional info

Devices that share the same IRQ with other devices are recognized by having the same (PCI) value. Devices that have positive (PCI) values are working in Line-based interrupts mode. Those that have negative (PCI) values are working in MSIĀ (Message signaled interrupts) mode.

IRQ are automatically allocated by the motherboard BIOS. Ideally, latency sensitive or I/O devices like sound cards, network cards, storage (SATA, NVME, SCSI) drive controllers should have their own IRQ. Having two or tree such devices on the same IRQ could impact the performance or functionality of those devices.

Avoid IRQ sharing by changing the interrupt mode to MSI

In order to avoid IRQ sharing between devices, you could change the interrupt mode to MSI for some of those devices with MSI Utility.

Some notes on changing the interrupt request to MSI:

  • Be advised that not all devices will work in MSI mode and some, if changed, may prevent Windows from booting. Some of these devices are listed in the table below.
  • Before using the MSI Utility, update the drivers as some newer drivers might switch to MSI by default. Try searching for them on the original chip manufacturer and not on the motherboard manufacturers page.
  • You can disable those devices that are not used (for example LAN, onboard audio card, Bluetooth etc.) via BIOS or Device Manager (in Windows Run or Search type devmgmt.msc or right click on Computer->select Manage->select Device Manager)
  • For devices you don’t know they work after changing interrupt mode to MSI, change one device at a time after which restart the system so that if your Windows does not boot anymore you know which device was the problem.
  • If Windows does not boot anymore:
    • Windows 7: When the system starts, tap F8 until the Windows boot menu appears and select the “Last Known Good Configuration” option.
    • Windows 8/10: When the system starts, tap F8 until the Windows boot menu appears, select “safe mode”, launch MSI Utility and revert the latest change you made. If “safe mode” does not work, in the boot menu press F10-> F1-> Troubleshoot-> Advanced Options-> System Restore-> pick the most recent restore point.
Device and driver MSI compatibility status
Device/driverCan be changed to MSINotes
ASUS Xonar PCI/PCI-e cards
  • Xonar DG, DGX, DG SI, DS, DSX, D1, D2, DX, D2X, HDAV, HDAV Slim, ST, STX, STX II, Xense.
  • Other C-Media CMI8788 audio chip based cards: Auzentech X-Meridian & X-Meridian 2G; HT Omega Claro Plus, 2, Halo, eClaro; Razer Barracuda AC-1.
NoSwitching to MSI mode will prevent the system from booting
Marvell Yukon 88E805* PCI-E Gigabit Ethernet ControllerNoWill work but the device will not be stable when it is intensively in use and the will lose the connection
Realtek PCIe GBE Family ControllerYes
AMD SATA storage controllerNoOnly if it is switched by the drivers themselves
Intel AHCI and RAID storage controllerNoOlder drivers probably won’t work. Newer drivers of Intel Rapid StorageĀ  v11.7 and above enable it by default
Standard AHCI 1.0 Serial ATA ControllerNo
NVIDIA GeForce & Quadro display adaptersYesWith newer drivers might be switched by default. On older drivers you can manually switch it
Intel(R) ***** Familiy PCI Express RootYes
Intel(R) ***** Express Chipset PCI Express Root Port *Yes
Intel(R) Management Engine InterfaceYes
Intel(R) USB 3.0 eXtensible Host ControllerYes
Intel(R) ***** SMBus ControllerNo
Intel(R) ***** Family USB Universal Host ControllerNo
Intel(R) ***** Family USB2 Enhanced Host ControllerNo
PCI standard PCI-to-PCI bridgeYes

* = any.

List will be periodically updated. Some of these could work with newer drivers.

Applies to the following OS:

  • Windows XP, Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2012, Windows Server 2016, Windows Server 2019

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