Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Which is faster - two 500gig Western Digital hard-drives in a RAID configuration or two single Western Digital hard-drives?

share|improve this question
too vaugue to give a real answer to – August Oct 6 '09 at 17:07
What is this being used for? How is RAID managed?-Hardware or Software? – Dave M Oct 6 '09 at 17:15
This belongs on – Izzy Oct 6 '09 at 18:54
You need to give lots more details - hardware raid or software raid. Layout of disks (see Even the intended use (do you want faster reads or writes?) – Coops Oct 6 '09 at 19:54

Assuming all the drives involved are the same type: Two drives in a RAID-0 configuration are faster than a single drive, which itself is generally faster than two drives in a RAID-1 configuration.

RAID-0 alternates sectors across each drive, so reads and writes can be sent to both drives at the same time, making it slightly faster. It also has a total capacity of the sum of both drives.

A single drive has only itself to worry about, but has only its capacity.

RAID-1 has all content on both drives, meaning that writes are slower since they have to be explicitly sent to two drives instead of one. However if the RAID is set up correctly, reads can be stepped across drives leading to increased performance. In general though, RAID-1 turns out to be slightly slower than a single, non-raid drive. RAID-1 capacity is only the value of the smallest disk in the array, however the array can continue to function if one of the drives in the array fails. (The "R" in RAID means "redundant".)

share|improve this answer

The RAID controller will certainly play a part in any scenario.


If you are using a hardware RAID solution it will be faster to RAID 0 than to have two seperate drives. RAID 1 would be the same or nearly the same speed in most scenarios since controllers are optimized for mirroring out to multiple drives.


Software RAID will always be slower than hardware RAID or just two regular drives. Avoid this at any cost for mission critical usage.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.