So I just upgraded to a X99 system from a X58 and have all the latest drivers installed. Windows installed my sata/raid controller driver and afterwards I installed the latest RST driver from intels website.
Heres where things get strange for me. I was doing a test of my Samsung 850 Pro on AS SSD and saw in the top left corner that it was using the iaStorB driver. 
I have 2 WD Raptors in Raid 0 that are about 4 years old and they are using the iaStorA.sys driver.
ASUS X99 Pro USB 3.1
i7 5930k
Just to note, I have done a lot of Windows 10 Re-installs on this pc and I think last time I reinstalled, I had a Iastorf filter driver and a iastora driver on the non raid controller. I would like to know what will net me the best results when considering speed of the system.
Are my drives/system/controllers using the correct drivers for my system?
Thanks!
@ Forkinator:
Welcome at Win-RAID Forum!
This is the correct driver for the Intel sSATA AHCI Controller.
Contrary to other Intel Chipset systems the X99 ones are controlling the on-board SATA ports by 2 different and independently working SATA Cotrollers.
Although I don’t know much about the usage of X99 Chipset systems, I think, that your current Intel SATA configuration and the in-use Intel AHCI and RAID drivers are ok.
Merry Christmas and a Happy New Year!
Dieter (alias Fernando)