RAID Configuration on ASUS Crosshair V Formula Z

Hello All,
I am trying to build a PC with RAID configuration. The main configurations are

Motherboard Criosshair V Formula Z
CPU FX9590
SSD 5x 120GB Sandisk SSD Coected on Sata port 1-5

I have set
Port1-4 RAID
Port5-6 RAID
Board SATA RAID ROM Legacy ROM

Within the AMD ROM Utility, have set the RAID array to use RAID mode 5 with all the SSDs totalling 507.99GB. When I restart the BIOS detects it as one drive 'Logical Drive 1'

Problem
When I try to install ubuntu on the RAID. Ubuntu detects the storage as 5 drives of 120GB sda-sde, as if the BIOS RAID configuration never existed. I would have expected the RAID controller to present the memory as 1 single chunk of 507GB.

- Can somebody please help? Am I missing any configuration?

- Is it safe to assume "Crosshair V Formula Z" has actual "hardware" RAID controller and not the fake controller which relies on OS to perform RAID read/writes? It has SB950 controller and all the tools I can find supports Windows only.

Many Thanks,
Tony