RAID 4 vs RAID 5

With respect to performance, RAID 5 will generally outperform RAID 4. With RAID 4, you have a dedicated parity drive, which means that the parity drive will be a bottleneck in high I/O situations. RAID 5, however, spreads not only the data but also the parity information across all drives in the RAID set.

Why is RAID 4 not used?

Because data is striped in RAID 4, the records can be read from any disk. However, since all the writes must go to the dedicated parity disk, this causes a performance bottleneck for all write operations. RAID 4 is not commonly used.

What is RAID 5 used for?

RAID 5 is one of the most common RAID configurations and is ideal for application and file servers with a limited number of drives. Considered a good all-around RAID system, RAID 5 combines the better elements of efficiency and performance among the different RAID configurations.

How does RAID 5 work with 4 drives?

As a reminder, the RAID 5 requires a minimum of 3 hard drives. The RAID 5 spare has 4 disks; the fourth unit being used as a spare. This guarantees the safety of your data, with the spare only being used when one of the disks fails.

Which level of RAID is best Why?

The best RAID configuration for your storage system will depend on whether you value speed, data redundancy or both. If you value speed most of all, choose RAID 0. If you value data redundancy most of all, remember that the following drive configurations are fault-tolerant: RAID 1, RAID 5, RAID 6 and RAID 10.