How does raid 0 work?

[Amd For Ever]

I know raid zero gives you performance and splits up your data into stripes but does it use twice the space? When you store like a game on a harddrive (say 2gb) does it use 2gb on each drive, 1 on each? The reviews I have seen show a good boost in performance with raid 0, but I don't want to lose half my hd space as I use a lot. Are there only temporary swap files on the harddrives when you run a program and the actual program is the regular size? Do you need to leave more space open on raid 0 drives? What are the differences between seperate drives and ones in raid 0?

[mrmagoo_83]

No, it uses 1GB from each drive.

The main difference between a RAID 0 configuration and a regular setup is the fact that if either of those drives in the raid die you loose everything, unless you are running 0+1, but then you loose a little performance.

I am no RAID expert so if I got that wrong I apologize, but off the top of my head I believe that is correct.

[BillLeeLee]

No, you have the full hard drive space available. If you have 2x160 GB, you have 320GB at your disposal. However, if you have two drives of different sizes, RAID will treat them as 2x the capacity of the smaller drive. For example - a 120 with a 200 in RAID 0 will make it 2x120, the extra 80 on the 200 is ignored.

And yeah, it writes part of the file to one drive and part to the other.

This also increases chance of data loss, as mrmagoo has said. If one drive goes, the array goes (no redundancy, it's technically not RAID), and so does the data. For any critical data, RAID 0 is not a good idea.

[FlatLine84]

No, you have the full hard drive space available. If you have 2x160 GB, you have 320GB at your disposal..

This also increases chance of data loss, as mrmagoo has said. If one drive goes, the array goes (no redundancy, it's technically not RAID), and so does the data.

Glad to hear somone say "increases the chance" and not "Doubles the chance".

[BillLeeLee]

Yeah, increasing and doubling are different. I used to say doubling, but probabilistically, the drives probably don't have an equal chance of dying.

[DougLite]

A visit to RAID.edu (http://www.acnc.com/raid.html) is a good start. After getting the basic concepts in your mind, there's some high level stuff to learn.

- RAID-0 does not increase seek performance (ie, how long it takes for the drive(s) to reach the start of a file and begin transferring), so it does not boost performance when working with small files and frequent seeks.
- RAID-0 will give a boost to linear tasks. Such tasks include multimedia work with huge video/audio/graphics files, Windows XP's optimized bootup process, and generic file transfers between disks. Some games also exhibit linear access patterns that scale well with RAID-0. Many games show no gains from going to RAID-0.
- RAID-0 will never deliver double performance. Gains range typically from 0-25%. Improvements of about 50% may be realized in straight file transfers.
- RAID-0 will not make slow drives fast. A single 73GB Raptor will still deliver better performance on the desktop than the latest and greatest 7200RPM drives in RAID-0 in most usage models.
- RAID-0 substantially reduces the reliability and uptime of the volume stored on the array. This is because all members must be present and operational to hold data.
- RAID of any type makes your data more vulnerable to corruption, viruses/malware, user error, and failure of any hardware other than the physical disks (PSU, mobo, etc). This is because your data is stored in one array that the OS sees as one volume.