looking to set up a photography PC slash storage. Below is my disk drives

500GB SATA

2.0TB SATA

2.0TB SATA

500GB ePCI NVMN --- use this as the PC

It occured to me, if I partition the 2TB in 4x500GB , and same for the second one, I have 9 500GB partitions. Allowing Raid with 3 partions (one from each drive)

My Question is: the remaining 1.5TB in 500GB chunks on each drive (so 3TB total) - can I then use this as per normal, as in not part of the RAID setup?

Thanks

EDIT: Raid Mirror if it was just the 500GB x 3 , so mirror and have an extra redundancy drive? Open to Stripe, but as I understand it, that would get me 3x speed at say a 500GB across three drives, but zero redundancy, in fact higher risk of data loss if one of the three HDD failed