Hello PityOnU, I’m sorry to hear that you are having issues with this system.
The Celeron 2955U processor is part of the Haswell family.
The following URL will show you the correct site from where you can download Intel generic drivers available for your processor.
Bear in mind that these drivers are for Windows operating system.
Intel does not test and validate Intel® NUC on Linux, however we know that a lot of NUC owners are using it successfully.
I will suggest you checking your Linux distro’s website and forums for peer assistance with this issue.
Thanks for the response and information sylvia! Unfortunately, using the drivers you have linked does not solve the problem - I am still unable to use HDMI audio under Windows 8.1.
Is there anything you need from me that would help identify the exact source of the problem? Again, I am not the only one experiencing it.
PityOnU, this issue was reported to our engineers. You would be able to get additional information about this on this thread.
This situation is still under investigation. https://communities.intel.com/message/218663
i'm currently using the same system as PityOnU: Asus M004U with Windows 8.1 64-bit except I'm using a USB soundcard with an optical output (Turtle Beach Micro II). This configuration works well with XBMC: I get dolby surround sound from my Denon receiver via the optical output of the USB soundcard. The problem happens when I run Netflix and select Dolby Digital+: The framerate drops to maybe 2 frames per second and there is no sound but everything run's smoothly if I select Stereo. Maybe this is caused by the same thing as what PityOnU is experimenting...