what i RAID 0?

i am buying a new laptop, but i am confused about the raid 0 thing, tried to google it but it just confused me more. so what is it? is it the combination of 2 HDDs? are they gonna show up as 1 or 2 separate drives in "my computer"? do they have to be equal size? what are the performance difference? please help~

 

When in doubt, always Wikipedia.

http://en.wikipedia.org/wiki/RAID_0#RAID_0

 

I will try and say it in my own words.

It is a combination of 2 drives, however they show up as 1 drive in windows. Say each is 200gb, it will show up as 1 400gb drive.

They have to be of equal size and speed.

It performs a little better because it splits half of the data to each drive so say you need to pull a 10mb file, on raid 0 it would put 5mb on each drive, thus reducing the time it takes to pull that file in half. You don't get double the speed in practice though, but a gain is given.

The bad thing about this is that if one hard drive dies, you will lose the data of both drives.

 

Yup nizzy sums it up nicely.

Basically two drives are working together on reading and writing files.

 

yea, raid 0 is for striping.

good for speed. but im not a fan because i work with media, and if i were to lose some of my project media, id **** bricks

i think that raid 5 (pretty sure thats the right one) is the best, though you couldnt do it on a laptop. it has striping for speed and it has parity, which basically backs up all your files so in case your harddrive bites the dust you arent sitting in the fetal position about it.

 

If I remember correctly, it's an option when ordering a Sager NP9262, as it has a 3rd HD option.

 

"It is a combination of 2 drives, however they show up as 1 drive in windows. Say each is 200gb, it will show up as 1 400gb drive."

This is correct.
I have two 200Gb 7200rpm hitachi harddrives in raid 0, and they show up as a single 400 Gb drive. 400Gb is really 372Gb of usable space.
Raid 0 definitely males the system faster.

K-TRON

 

Actually 3 drive raid 5 configs really arent that reliable. In servers, 2 drives tend to fail at the same time quite often. This results in a total loss of data. (Personal experience has shown this and google did a hard drive analysis of their server farms ... they have LOTS of hard drives) and it showed that exact same make and model drives that came from the same lot were likely to fail very close to each other. Thus, i would use no less than a 2 drive redundancy. (4 drives total, 2 being redundant.)

For a home environment though, raid 5 is more than enough if you do weekly data backups on an external drive that is not attached to the systems when not backing up files.

 

Yeah for "real" RAID (level 0 is not really considered "real" RAID as there's no redundancy) - the optimum choice for consumers and home users is betweeen RAID 5 and RAID 10 (1+0; or 0+1).

Assuming you have 4 drives in the array, Raid 5 trades more useable space at the cost of some performance. The capacity of the volume Windows would "see" is essentially the total capacity of 3 drives. In Raid 10, you gain a bit in write performance - as there is no parity data; but the trade off is you only "see" the capacity of 2 out of the 4 drives.

Both can tolerate the failure of 1 drive, and seamlessly rebuild/recover from it. But if 2 drives fail, it would cripple all useable data on a Raid 5 volume; and under the 'ideal' failure conditions you may not have have lost any data from a Raid 10 array - but it's down to chance and having the 'correct' combination of two drives failing.

May I remind anyone who's reading thus far, who may have some interest in building a Raid array for home/personal use - that RAID IS NOT A SUBSTITUTE FOR BACKING UP! It offes redundancy - the ability to recover from a physical drive failure with less downtime. It should NOT act as your backup strategy! You MUST continue to externally backup your data.

 

its why i said you couldnt really do it in laptops (unless their makin 3 hdd laptops nowadays, but w/e) i wouldnt do it with less than 4 hdds. and yea, id also back up on an external drive haha. cant be too safe.

 

lol jks

OP: i dont think you should be messing around with RAID unless you know what your doing. RAID 0 can leave you with nothing.

You might wanna consider a SSD drive if you want speed

 

Before anyone overstates the performance advantage of RAID 0 too much, in most common scenarios it's in the order of 0-5% faster than a single disk.
Don't expect miracles on that front, unless you're running a file server or doing DVD editing on a daily basis.

 

I saw some of the HDTune Benchmarks and they seem to be really fast. No where near 0-5%

 

HDTUNE shows the maximum read/write cycles your drives can handle.

The problem with Raid 0, is that half of the data is on each of the drives. That means that the latency essentially doubles.
In real life performance, both harddrives have to work together and decide on how to put the data together, which usually shows about a 10% performance gain.
A single harddrive is almost as efficient because all of the data is on a single drive, and the harddrive does not have to think about how to put 1 and 1 together for every data cluster.

HDTUNE is a benchmark, so it is showing the performance when doing harddrive intensive programs like video editing and such.
One will notice that most programs only boot slightly faster in Raid 0.
One would expect that raid 0 would equal 1/2 load times but unfortunately it does not work that way.

K-TRON

 

does putting two hd in raid 0 increase chances of hd failure of anysort?
raid 0 would be like simply having two harddrives both used for storage, but with a speed bonus yea? and that they'll just show up as one hd.

 

Yes, they are both for storage and speed.
Raid 0 is not as safe, because of one harddrive fails, everything is lost.
This is because part of the data for every file is on both harddrives.
When one piece is lost all of the data is deemed useless.

If you buy two harddrives for your laptop, then your probability of failure increases, cause there are now two drives.
If the drives are both stable, than you will be fine.
I have had zero issues with my Raid 0 array in my laptop.

K-TRON