Audio Microsoft UAA bus driver for High Definition Audio is causing high hardware interrupt


I am running XP SP 2 on Intel Motherboard DH55TC, Core i5 CPU. UAA High Definition Audio class driver is resulting in high hardware interrupts that uses upto 10 to 12% of CPU. The interrupts goes away if I uninstall UAA Bus driver through Device Manager. But this also disables RealTek audio driver which means I hear sound no more.

I tried updating the UAA driver to Version 1.0a but still the hardware interrupts wont go away. Please help how to fix this issue.
Thanks for the suggestion. I downloaded and installed the driver but still see the interrupts. The actual problem is with Microsoft UAA driver and not realtek driver. Realtek drivers depend on UAA driver to work, so when I disable UAA driver, realtek driver also stop working.

I read in some forum, someone says that making IRQ same for VGA and HDMI would fix the interrupts. He suggests changing the sound card from one pci slot to other to change IRQ. But my sound card is inbuilt, so I have no option of changing its slot. Is there any other way of changing IRQ?

At present, in my device manager, IRQ for Microsoft UAA Bus Driver for High Definition Audio is 22.


Posts: 6,429   +186
I have some information but not a solution :(

1) As you noted, MS UAA bus driver is required. This is because
> You have Hi Def Audio on your computer
> Hi Def Audio requires both an audio controller chip PLUS a sound card ([post=924659] How Sound Card Hardware Connects to the computer’s PCI and USB bus[/post])
> MS UAA bus driver is for your onboard audio controller chip vs. Realtek which is for your onboard sound card

2) You can also try upgrading to XP SP3

3) Have you always had this problem? or did it just start occurring? What tool or how are you tracing the interrupts to MS UAA driver? (just curious)

4) You mention HDMI.. does this problem only occur when you use HDMI? or does it occur with any audio devices?

/* edit */
Also, have you run Windows Update and run Custom updates??? Be sure to install any hardware optional updates which might appear. Keep re-running Windows Update / custom updates until no more updates are available
I previously had SP3. The problem must had been there for months but I never noticed it because I did not feel any impact in computer's performance. Then one day, I just noticed in task manager, some thing other than a process is taking up CPU usage. I thought it might be a virus and re-installed OS. Initially, the interrupts would not be seen but would just come back after I install the drivers. Finally, I was able to confirm it is Hardware interrupts using a tool called process explorer (It can be downloaded for free).

Then I narrowed it down to UAA driver, after spending many hours in internet. I am able to disable or enable UAA bus driver through device manager in XP.

I am not much familiar with HDMI. Is it possible to use audio device without using HDMI?


Posts: 6,429   +186
I was able to confirm it is Hardware interrupts using a tool called process explorer
Good. :) I use Process Explorer myself for many years. It's a great tool :grinthumb

I am not much familiar with HDMI. Is it possible to use audio device without using HDMI?
HDMI is a new type of cable connector standard. It can carry both audio and video over a single cable. The connector of an HDMI cable looks something like this

Your computer should also support other audio out plugs (e.g. for headphones). Have you check interrupt levels without an HDMI cable plugged in?

3. Normally, IRQ levels are best left managed by Windows. This requires an up-to-date "ACPI compliant" BIOS
> What version BIOS are you running? (Boot your computer. When the flash screen appears, it should display the current version # of BIOS installed)
> Then go to Intel site and what is latest BIOS for your motherboard?
> How do they compare? I don't recommend a BIOS update yet (as they can be tricky and you must be sure you are loading the right BIOS) but first double check if it appears you are running with latest BIOS
Thanks for reply. I do not use the cable of the sort you attached as image. I only use audio out pins (headphone pins).

Regarding the BIOS, I already knew mines is old and I also found latest version available in intel website. But I feel paranoid about flashing BIOS. I read the release notes and did not find any fix related to this issue.
Found the root cause

I found out the root cause of the issue. It is with Intel's motherboard and not Microsoft's driver.

I upgraded to Windows 7 but still saw the interrupts. So I decided to live with the issue. I disabled UAA driver through device manager which would stop the interrupt and sound. I would enable it only when I need to hear sound. But few days back I encountered a new problem. The computer started to turn on and off repeatedly even when I do not press the power button. When plugged, it would turn on automatically, remain on for a few seconds, then turn off and again on! This cycle repeats.

Then I took it to the shop where I bought it. They told it is an issue with motherboard. As it was covered by warranty, they sent it to Intel and got me a replacement in few days. Now with the new motherboard I do not see any Hardware interrupts. The CPU performance remains at 0 or 1 in task manager.

So if anyone encounters the same problem, the issue is most probably with the Hardware (motherboard) and not software (device drivers).


Posts: 6,429   +186
Hi arunkumar6012

Thanks for taking the time to let us know what ultimately happened. It's both interesting and helpful to learn the facts of the solution!

Happy Computing!
I know my post is years late, but I just want to make everyone aware that this is still an ongoing problem, with hundreds & hundreds of people when Mobby makers use the Realtek HD driver in combo with Intel onboard sound chips and MS AUU bus driver. It's really not an issue sometime, it can happen anytime. In matter of fact MS build a time bomb that after a certain date the UAA driver would not be compatible with Realtek HD. This wasn't known until the bomb exploded. MS in turn made a fix (which doesn't solve the problem for everyone) by coming out with KB888111 update. In some cases it has helped but in others the KB hasn't helped one bit. Those people have NO sound and are forced to buy another motherboard. It's really a hit and miss if the KB888111 can do the job. There are 100's of suggestions floating around, none are guaranteed to make the Realtek HD load to give sound. It has nothing do with Intel, but the combination of all three
requirements - Reaktek, Microsoft, & Intel. Wish they would get together.
If someone can come up with a true fix, I'd love to hear about it.