I know that NAS drives are specifically designed for the constant usage. meaning a system that is on 100% of the time. Is it possible to install these drives in a desktop computer that needs a more reliable storage system of drives.
What I would like to do is install 12x 8TB drives and raid most of them using an Intel controller card. So, is it OK to do this or should I use the Enterprise version of the drive?
You should look at the data sheets and technical specifications of the drives you want to compare. Each vendor gives detailed information about
With those values you can then approximate if you should use the cheaper or more expensive ones. You should also into account costs for replacement of disks (procurement, shipping, installing/removing, disposing of old drives) and financial incentives (taxes, writing of over number of years, warranty on desktop systems).
If you just want the raw numbers, I suggest also taking a look at the Backblaze drive reliability statistics found on their blog.
There's two things here for you to know - many systems have multiple disks installed and that's fine but any given disk has what's known as a 'Duty Cycle' - this is the amount of time it's designed to run in order to maintain it's specified reliability figures. Most/many top end disks have a 'Duty Cycle' of 100%, meaning they can be operated hard for their entire lifetime, some cheap ones have as little as 30% meaning they should only be driven hard for 8 hours or so per day, going past this will lower the reliability of those disks. So look at your usage pattern and ensure your disks match that ok.
The second one is far more serious - many people come to serverfault without knowing that RAID 5 is essentially dead as a usable technology and learn that the hard way. The issue is well documented but boils down to the size of modern large, cheap disks and their 'unrecoverable error rate' - meaning that if you build a R5 array of large (>1TB) disks then when a disk fails and you replace it you're almost certain to introduce an 'unrecoverable error' into your data as the data is rebuilt onto the new disk - it's just a math thing. As I say this is well known in the sysadmin community but disk manufacturers keep enabling it, which really shouldn't be in 2016. So by all mean make this NAS of yours but please only trust R1/10 and R6/60 - they're the only games in town these days.
It is usually SATA so yes it will work in any computer, a NAS is a computer as well.
Whether it makes sense or not is a different question. These drives usually are designed to be low-power which often means 5400 rpm. This means you get longer seek time over regular desktop drives. Throughput will largely depend on the controller and RAID level in this case. Also it is less versatile than a NAS this way.
The alternative would be to get a board with many SATA ports like Intel Avoton, and install FreeNAS. Then buy two cheap 10 GBit cards (~40 USD) to connect to your computer. This gives many advantages, the most important of which is ZFS.
