does RAID add speeds?

[ITechFreek]

Does putting Hard drives into RAID add the RPMs? If not please explain what it does do. Thanks!

 

[USAFRet]

Does putting Hard drives into RAID add the RPMs? If not please explain what it does do. Thanks!

No, it doesn't 'add the RPM's'

What does it do? This depends on MANY things.
There are multiple levels of RAID. Read more here: https://en.wikipedia.org/wiki/RAID#Standard_levels

What benefit are you looking to gain?
What hardware do you have?
What are you planning on using this for?

 

[Shaun o]

In simple terms, each hard drive spins at a set speed while in operation.

For example two drives in a Raid 0 configuration spin at 7200 Rpm.

It is not the speed that the disks spin at but the fact that each of the drives can read a set amount of data at a given time.
If you Raid two drives together, you are increasing the amount of read and write operations that happen due to doubling the amount of read and write heads in synchronous operation in a raid 0 array for example, by pairing them together to act as a single drive.
A larger amount, or block of data can be read, or written in the same amount of given time it would take a single drive to perform because to equal the Data transferred by a raid 0 configuration of drives.

The single drive would have to perform two read or writing sessions of data, to equal the size of data a raid 0 array would do in one read or write session.

You are moving a larger block of data in less time. In a Raid array the bandwidth is increased, the amount of data you can physically transfer in one request for reading or writing operations.

 

[emdea22]

If you don't know how RAID works its probably a good idea to stay away from it. There are different kinds of RAID.I will keep it short - if you want more info there are plenty of articles.

RAID has nothing to do with RPM - you can RAID SSDs that have no moving parts.

RAID 0 intertwines two storage units (like HDDs) creating one single virtual disk that has the information spread on both drives as equally as possible. For example if you write 10MB of information on your RAID 0 array then 5mb will be on your first drive and 5mb on the second - usually. This can depend on the way you setup your RAID0 but the general idea still applies.
Both read and write speed is increased with RAID0 but its never going to double - best case scenario it will almost double.

RAID 1 works the same way as RAID0 but in this case the information isn't spread but its doubled. Every bit of info on the first drive has a mirror image on the second drive thus halving the total capacity of your drives. This provides data redundancy. Example:
2x 1TB HDDs in RAID 1 will provide an effective capacity of 1TB total.
Read speads are increased almost the same as RAID0 but write speeds stay the same as if you were using a single drive.