Asus x99 PRO post code D4 with Samsung 950 PRO

Hello,


I am experiencing a black screen hang-up during boot. The screen shows the ASUS motherboard logo, then black screen hangs for about 1m and 15seconds, then proceeds to boot into windows. During he long hang, motherboard shows QCode "D4" (PCI resource allocation error. Out of resources).


Here are my specs:


Asus X99 Pro USB 3.1
Core i7 5960X
EVGA 980 Ti (Sitting in top slot)
64gb G.Skill Ripjaws 4
Samsung NVMe 950 PRO
ASUS Thunderbolt addon card (Second Slot)
EVGA Supernova 1050W PSU
Windows 10 Pro Latest Build (10586.164)


The motherboard has latest BIOS (2101).


Things I've tried


- I have the system overclocked mildly to 4.2Ghz, I tried resetting BIOS to default - no go
- Clearing CMOS - no go
- Samsung has an NVMe driver (version 1.1), this is installed - no go
- Tried running only with one stick of RAM, and only the 980Ti to eliminate any hardware conflicts - no go
- Since this is supposedly PCI Resource error, I tried running the 980Ti in second slot - no go
- Tried switching Fast Startup on/off both in Windows and BIOS - no go
- Tried re-installing Nvidia drivers fresh - no go
- Ran Windows Performance Analyzer Boot Trace to see if anything else hangs up the boot, nothing showed - no go
- Rebooted with only basic services - still hangs (this tells me it is not a startup/services related issue)


My suspicion is that this might be a driver conflict with Windows 10 and the Samsung driver.
In my Device Manager, under Disk Drives - I have "NVMe Samsung SSD 950"
under Storage Controllers, I see "Microsoft Storage Spaces Controller" and "Samsung NVMe Controller"


I've tried uninstalling the Samsung NVMe Controller, but after reboot, I get BSOD "INACCESSIBLE BOOT DEVICE", and I'm having to run the Automatic Startup Repair to get back into Windows. Then the Samsung NVMe Controller re-appears.


The Microsoft Storage Spaces Controller does not have an option to be uninstalled...


At this point, I'm not sure what could be the problem, I seemed to have tried everything.


If someone has experienced this or knows a solution, this would be highly appreciated, seeing I've already spent countless hours on this.
One would expect to have a blazing fast boot times with hardware like this, but I guess things are not always so smooth..


Thanks for reading,
Lukas

UPDATE: I have solved this issue, for anyone experiencing this, I got my boot time to around 45secs by disabling the CSM. If you don't want to disable it, just set the PCI to "UEFI FIrst" or something similiar depending on your mobo.


Thanks!