USB - HD disk spin down good?

[jbombs16]

I have setup my n66u with a 4 bay raid enclosure. I want to know if it is better on the hard drives to have them spin down during inactive times or to leave them on 24/7.

I have read that it is hard on the drives to spin up/down and I am not really concerned with power consumption.

Can someone provide some insight on what is better to extend the life of the drives? - constant on vs. Spin down

I am using the enclosure for media streaming so it isn't necessarily going to be accessed all the time. I was thinking of having the drives spin down after 2-4 hours of inactivity. However, I just want to make sure that won't expedite the eventual failure of the drives.

If spin down is recommended, what would a good time to set for the period of inactivity?

Thanks

[RMerlin]

2-4 hours would be a good value IMHO. For the usage scenario you describe, I doubt you'd be accessing it multiple times spread across the whole day (or at least very infrequently), so 2-4 hours would ensure it gets spin down at least for the night, and remain spun down until the next access which, I would assume, would most likely occur the next evening at the earliest.