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 11, Windows Server 2008, Windows Server 2012 and Windows Server 2016, Windows Server 2019 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)

About IRQs and IRQ sharing

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 MSI (Message signaled interrupts) mode.

IRQs 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 using different PCI or PCIe slot

You can avoid IRQ sharing between devices and fix a IRQ conflict if you change the PCI or PCIe slot for the devices you want to get assigned with a different IRQ.

Avoid IRQ sharing by changing the interrupt mode to MSI(Message signaled interrupts)

Another way to avoid IRQ sharing between devices is to 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 8/10/11: 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(Message signaled interrupts) 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.
Creative X-FINoReports say there is no audio when switched to MSI.
Marvell Yukon 88E805* PCI-E Gigabit Ethernet ControllerNoWill work but the device will not be stable when it is intensively in use and then it 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 Storage  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.

Information in this page applies to the following OS:

  • Windows XP, Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 11, Windows Server 2008, Windows Server 2012, Windows Server 2016, Windows Server 2019
Donation notice
Was this helpful? Please consider supporting us by making a donation.

Leave a new commentReply to comment

Comment received.
Your comment may be held for moderation. If it does not show up immediately, please be patient. Comments have to comply with these rules:
  • English language only
  • Don't post insults or threats
  • Try to keep the discussion constructive and informative
  • Don't post questions without doing a search beforehand
  • For replies to individuals regarding the SAME discussion, use Reply to write to that individual. For a NEW issue write a new comment.
  • Make your comment easly readable. Write the product names how they are originally written or at least capitalize their first letter. Write "i" as "I". Add a space after end of a sentence and beginning of another (e.g. ".I" -> ". I").

We've noticed that you're using an AdBlocker

It's not just you, over 66% of our site's visitors are blocking the ads.

Please disable adblock for this website and refresh this page if you:
find the content useful
want us to create more useful content and software
want tech support through the comment section

The ads are placed so that there is minimal interference with page reading. There are no pop-up, pop-under or sticky ads.

Alternatively, you can support us by making a donation.