The confusion of RAID

[177ine177ine]

Hey guys, I'm a noobie computer builder and in September I'll be building my new Conroe. I've been asking around for RAID but I actually haven't sat down and written a new topic in the Hard Drive forum for some odd reason :? . My new system will be:
Conreo E6400 cpu
7900gt gpu
asus p5w dh deluxe mobo
3 X 250gb Sata 2 WD raid edition hard drives
600 watt gamexstream ocz power supply

My motherboard says this about RAID support:

Storage Devices
PATA 2 x ATA100 up to 4 Devices
SATA 3Gb/s 6 x Internal Serial ATA 3.0Gb/s ports
1 x External Serial ATA 3.0Gb/s port
SATA RAID RAID 0/1/5/10 Matrix RAID
Additional RAID Controller Jmicron JMB363
Silicon Image 4723

My questions are simple.
1. With my 3 hard drives can I set up a RAID 5 on my system?
2. Can my computer handle this RAID 5 and would I get good performance compared to let's say the 10000rpm WD raptors?
3. Do the hard drives show up as one hard drive in the windows explorer?
4. How would I set up this RAID 5 if at all?

Sorry to bother you guys with so many questions but I'm looking for answer before my build is complete in September. That's all the questions I can think of right now. Any help is greatly appreciated.

 

[j88per]

FWIW I think too much is made of raid these days. Most people know that raid is a tool or method to 'gang' up a bunch of drives and make them appear as a single drive. They hear about the "safety" of raid such as raid 5 and how 'protected' they'll be because of it.

However true raid is expensive. Most of these motherboards today aren't implementing true hardware raid. So it becomes expensive as a performance hit as well as a hit to your wallet. Plus, if you ever do encounter a failure at the controller level you're pretty much up a creek.

If I were going to build a brand new system today, I'd put my money where its needed most. Consider a new 750GB perpendicular drive or a couple of 500GB drives instead, more memory, faster CPU. I wouldn't mess with raid either. Not for a desktop platform.

If I ever encounter a problem with raid, especially on boot drives, I could possibly loose every thing and have to reload from scratch. It isn't like you can boot the windows cd and access your data or copy it to a network. (its possible in the corporate/enterprise, expensive for the home user)

If the cost of a 250GB hard drive is ~$100, then 3 would be about $300. I think a single 500GB drive goes for close to that? Or 3 independant (c: d: e drives then.

Raid 5 works this way - a chunk size or stripe size is determined when the reaidset is created, then that amount of data is written to the first 2 drives, an equal amount of data, called parity, is generated and written to the 3rd drive. So with a chunk size of 64kb, then 64kb is written to disk 1, another to disk 2, and then parity is calculated for disk 3, data & parity span all 3 disks. Thats great if I have 128kb of data, but say an 8GB dvd needs to be broken up accordingly. Thats a lot of CPU cycles to create parity. Imagine generating parity right when you're fighting some key creature in Everquest or trying to watch a DVD movie? Oh - that 3.6 Ghz cpu just paused.

Finally, after looking over your hardware list, I wonder why a 600w power supply is really needed. I thought conroe was supposed to be a much lower power chip. One thing to consider if you do build a raid or start adding drives is this. The amperage of each drive is different. Most manufacturers list it on their websites. Usually a drive consumes 2 amps when it initially spins up and 2 amps under heavy load. So your powersupply needs to have at least enough amps on the +12vdc to support all disks including cd/dvd drives & floppies. I run a 6 disk raid 5 I built myself on a 350v power supply. For 6 disks @ 2a each, 12v I need 288 watts total. (look up ohms law) That leaves me with 62w for fans, cpus, etc. (now I might go buy another ps, but not more than 450w )

Good luck & congrats on the new system