Hello,first MY RIG :

Asrock X99X Killer bios 1.9

5820k@default

gtx 780

16gb ddr 4 crucial

1 crucial mx100 512gb newest firmware

1 crucial bx100 250gb newest firmware

all bios settings default

I bought my Rig last year and half a year ago I decided to install linux.

At this time I used Ubuntu Mate 15.04 later Mint 17.3 beta.

I installed Windows 8.1 and later Win 10  in bios mode(not in ueft) and linux also

in bios mode.I set in the BIOS the CSM on and disabled secure boot and fast boot.

So,at this time I had a Dual Boot System.

But the problem was the following.

As soon I installed Ubuntu Mate 15.04 I got boot errors.the code said Code 99 and 09c.

Also when booting into Windows I got an unknown Usb Device in device manager.

The more often I booted into Linux the more often this problems appeared in Windows.

So I made a CSMOS reset and  reinstalled the hardware.

I booted 2 or 3 times fine but then the problems appeared again.

So I disabled the usb 3.0 controller in Bios and tested the different usb 3.0 modes.

But no luck.now every time I got the unknown device message in windows 8,1.

I tried the folowing:

-I reinstalled the device in device manager

-I upgreded to win 10

-I tested many different Usb 3.0 driver from AS Media

But had no chance.Also the boot problems didnt went away.

And every time  I booted into Linux the problems became stronger when switiching to windows.

But at this time I still thought it must be a driver problem or windows problem with USB 3.0

I didnt thought linux was the problem.

So I decided to RMA the board.

Now I have a new X99X Killer and installed WIn 10.It runs flawless.

After 2 month or so I decided to install Linux Mint 17.3 on it and the strange thing is I got exactly the same problems again.

It seems there is somewhere a dangerous problem when using linux.

But I need linux.