Hard drives array

[Ethan_56]

Is it good to use 4 hdds

 

[SkyNetRising]

Basically you can use as many drives as your system supports.
Limiting factors are available sata ports (for internal drives), usb ports (for external drives) and PSU power capabilities.

 

[Phillip Corcoran]

And even if there aren't enough ports, you can always use external hard drives.