RAID Questions

[barnacle]

I am thinking about setting up a RAID system. I have read that RAID 0 runs the best, but it will not backup your data in case of a crash.
If I were to get two 74gb WD Raptors and set them in RAID 0, I would have 148gb of space?
If I were to get two 74gb WD Raptors and set them up in RAID 1, I would have 74gb of space with a duplicate of everything I save?

If I were to get a 74gb WD Raptor and a 120gb Seagate, how would that work with a RAID system?

please help me out.

 

[[Matt]]

If I were to get two 74gb WD Raptors and set them in RAID 0, I would have 148gb of space?

yes but the drives would act as a single drive and speed increase is negligable over a single drive.

If I were to get two 74gb WD Raptors and set them up in RAID 1, I would have 74gb of space with a duplicate of everything I save?

correct.

If I were to get a 74gb WD Raptor and a 120gb Seagate, how would that work with a RAID system?

RAID would only see the seagate as another 74Gb drive and iirc they would both run at the speed of the slowest drive (not sure about the second one i will have to check that but i think im right)

 

[barnacle]

Alrighty, thanks man.

 

[DreamThrall]

raid 0 = striping. Requires 2 identical hard disks. Each disk gets 1/2 the info, which means the total diskspace will be the sum of both the HDs. If I recall correctly, since you will be reading and writing from both disks simultaneuously, disk access speed should double. (hardware raid only, not software)

raid 1 = mirroring. Also requires 2 identical hard disks... refer to matt's post

To be honest, I would go with either of those. With raid 0, if either of your disks fails, you're screwed. Granted, it isn't VERY likely to happen, but still twice as likely than with a single disk system. Raid 1 is a bit useless for a regular home computer.

If you can afford it, I would go with raid 5.. it requires at least 3 identical disks. raid 5 is parity, and this is how I understand it works.

It's like raid 0 AND 1 in a way. The data is divided into 2 parts, like raid 0. However, there is a 3rd part, a checksum, which is written to the 3rd disk. (note: you can have more than 3 disks, the data will just be divided into more parts). It works sort of like an equation:

consider x and y are the parts of data, and z is the checksum.

disk0   |   disk1   |   disk2
  x     +     y     =     z
  y     -     z     =    -x
  z     -     x     =     y

and so on.

This way, if one of the disks fails, the data can still be recovered because:

-if one the data parts is missing, the equation can be performed to calculate what the missing data is
-if the checksum is missing, you still have both the parts of data

this link explains everything fairly well:
http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel0-c.html

EDIT: That link starts with raid 0, follow links to the other RAID configs.

 

[Gunsnroses]

If I were to get two 74gb WD Raptors and set them in RAID 0, I would have 148gb of space?

yes but the drives would act as a single drive and speed increase is negligable over a single drive.

Wrong, my raid 0, is a shit load faster then my drives solo.

 

[Asus]

Raid 0 drives perform about the same in a number of cases but they also perform better and worse in others.
If you set your stripe size correctly then it should be quicker at writing larger files to both disks and small files to just one disk. Although the latency can hurt performance.

 

[Gunsnroses]

I see a HUGE difference. In my K8NSNXP.
I can load battlefield maps in about 10 seconds with my raid 0, with 2 sata 7200s, instead of 20 or more with my IDE 7200

 

[Gorgon]

INTEL has developed a technology called MATRIX RAID

its combine raid0,1 together so you can enjoy the power of the two HD + backup data at the same time.

to get it you require to buy new Metherboard at least 915 or 925.

AMD going to implement this tech in its new upcoming mobos

http://www.gamepc.com/labs/view_content.asp?id=matrixraid&page=1&cookie_test=1

 

[Gunsnroses]

isnt that the same as raid 0+1?

 

[Asus]

It's just like Nvidia's current nForce3 chipset. 4 SATA channels with Raid 0+1.

 

[Gunsnroses]

Yeah, thats what i thought.
My current board, supports 0+1 on IDE Raid.

Sata doesnt, but thats only cause 2 of my 4 satas are raid.

 

[blackeye]

You wont have 148 gigs, you will only have 138. I have two raptors in raid zero. Windows thinks of a gig of ram as 1024 mb's I think and the hard drive companies refer to it as 1000 mb's. Still a lot of space though. The only thing I regret about having raided hard drive though is every time I flash the bios I have to go back in a setup the raid, and sata ports again in the bios. It only takes a minute or so but its a bit of an annoyance. No data is lost though which is a good thing. The first time I flashed the bios I was cursing because I though I had ****ed up my hard drive and would have to reinstall windows but then I realized that you have to enable the raid config option in the bios again.

 

[Gunsnroses]

You wont have 148 gigs, you will only have 138. I have two raptors in raid zero. Windows thinks of a gig of ram as 1024 mb's I think and the hard drive companies refer to it as 1000 mb's. Still a lot of space though. The only thing I regret about having raided hard drive though is every time I flash the bios I have to go back in a setup the raid, and sata ports again in the bios. It only takes a minute or so but its a bit of an annoyance. No data is lost though which is a good thing. The first time I flashed the bios I was cursing because I though I had ****ed up my hard drive and would have to reinstall windows but then I realized that you have to enable the raid config option in the bios again.

Lol been there