I have just got 2 latest i5 NUC. NUC5i5RYK (the slim version) and NUC5i5RYK (the normal height version that supports 2.5" HDD).
The RYK's CIR module seems to be problematic. When installing official driver from Intel download page, it always says 'Can't find device!!' - Device Manager says the CIR device's HardwareID is ACPI\PNP0530. However the NUC5i5RYH (the thicker version) does not have this issue - Device Manager says the CIR device's HardwareID is ACPI\NTN0530.
The RYK was manufactured in May 15 whereas the RYH was manufactured on 11 Aug 15. The boards are supposed to be exactly the same. Both shipped with BIOS 0246.
I have Samsung SM951 256GB PCIe M.2 SSD and 16GB of Kingston RAM in it.
Here's what has happend so far:
1. Out of the box BIOS 0246. Installed Windows 7 with SP1 x64 from external DVD - all fine.
2. Initially I installed the official Nuvoton SIO CIR driver fine (SIO_CIR_win7_20120801_2.7.1005.exe from Intel download) - didn't notice anything wrong. This means it ONCE worked.
3. After I pretty much installed all drivers I went to update the BIOS to the latest 0350
4. Then my system won't boot. Researched a bit and realized that the new BIOS may not support PCIe SSD. So I flashed BIOS back to 0246.
5. From here I saw the 'Unknown Device' in Device Manager.
6. Tried uninstalling or running the CIR installer again, it wouldn't install at all saying that "Can't find CIR device!!"
7. I checked the Hardware ID of the "Unknown Device" which says ACPI\PNP0530
8. Tried reinstalling fresh system (W7x64), tried changing to Samsung 850 EVO 256GB M.2 SSD (fresh installation), tried updating BIOS to 0247, 0249, 0348, 0350 (the 03xx BIOS won't boot M.2 drives) - no good.
9. Tried installing Windows 10 x64 - direct to the new Windows 10 bluescreen so gave up.
I noticed the difference of PNP0530 vs NTN0530. NTN should be referring to NuvoToN while PNP probably just means it doesn't know the manufacture code. So it seems like my CIR is somehow disabled as per your description but it is clearly enabled in BIOS. Tried disable/enable again - no luck. Tried resuming from Sleep (S3) as per described in this post - NUC5i3RY*: Bug in BIOS Version RYBDWi35.86A.0249.2015.0529.1640 - but it won't be re-enabled like that post indicated (still 'PNP0530').
So I am wondering if the FIRST upgrade to 0350 has caused the CIR to be disabled forever even when BIOS setting says it is enabled???
Will try putting in normal SSD using the RYH's cable and install Windows 10 under BIOS 0350 tomorrow - let's see if the CIR can be 're-enabled' somehow.
Pretty bad experience - FRUSTRATING - especially when this is flagship product from Intel...