You can increase the power of HDDs by putting them into raid0 array, but You're having 100% more chance of failure, since "one data" are stored on "two" or more drives. I suggest using two SSD drives for OS/games, they will offer You comparable reliability as RoG PCi-e SSD drive, with higher performance, for lower price. I'm not encourage You to create raid arrays from all Your drives. E.g. I'm using one raid0 array atm., two raid1 arrays, and I have two independent HDDs, as "third option of failure". So far I'm pretty good. Although, I'm using raid1 arrays, for storage, not raid0. There You lose half of the space, but lower the fail ratio by 50% [not really, it could be 200%, and it could be 20%, depends on the health of both drives].