Comments about a RAID 0 setup

[Ozkar]

I want to get a 36GB Raptor with the FDB motor for my new system, but they are not available yet (anybody knows when will they be available??). I'm still not sure if I want to set up a RAID 0 array with 2 of those Raptors (I know what most of you are thinking: I should be banned from SPCR for even mentioning 2 Raptors in a single post ). However, I want to try a single Raptor first to check its performance, and to see if I would be able to handle the noise of a pair of these 10k rpm monsters. I definitely like performance, that's why I'm looking into the RAID 0 option on my Intel D875PBZ motherboard. I also don't want to spend too much money. $350 for 2 Raptors is what I'm ready to spend. I don't want to spend more than that. I know that the risk of losing data is bigger with RAID 0, but I think the risk of failure is still small enough, especially for a non-critical desktop system, am I right?? I've heard comments that make it sound like the risk of losing data while using RAID 0 is considerably bigger than using a single drive, but as far as I know, the risk of losing data just doubles. Of course, i'll back up important data, but it's not like RAID is unstable, or the Raptors are low-quality drives. Besides, I will be doing a lot of disk-intensive tasks, so I think I will benefit from using RAID 0. What is your experience with RAID 0? Anybody has a RAID 0 setup with 2 74 GB Raptors with FDB motors?

This thread from www.storagereview.net discusses the necessity of RAID 0 in desktop PCs.

This article explains the increase in data loss risk when using RAID 0




System (not finished yet):
Intel Pentium 4 3.2 GHZ with HT with Zalman CNPS7000-ALCU CPU Cooler
Intel D875PBZ Motherboard
1GB PC3200 RAM
80 GB Maxtor Hard Drive (For Data and backup)
Antec SLK3700BQE Case[/url]

[hyperslug]

I should be banned from SPCR for even mentioning 2 Raptors in a single post)

Mmm dunno why you say that. If it's b/c they might be loud, it's still worlds away from SCSI loud.

I definitely like performance, that's why I'm looking into the RAID 0 option on my Intel D875PBZ motherboard.

The Storage Review (SR) folks say you'll only notice a difference with large files.

I know that the risk of losing data is bigger with RAID 0, but I think the risk of failure is still small enough, especially for a non-critical desktop system, am I right?? I've heard comments that make it sound like the risk of losing data while using RAID 0 is considerably bigger than using a single drive, but I don't think the risk increases too much.

Well yeah risk is greater, and the Raptor is too young to have any reputation for reliability, good or bad. I have heard of a few Raptors failing quickly when they ran too hot, so keep them cool somehow.

i'll back up important data, but it's not like RAID is unstable, or the Raptors are low-quality drives.

Good idea.

I can't remember from stats class but I think you multiply the odds to get cumulative in-series odds. Like if a single Raptor has an 80% chance of surviving 3 years, Raptors in tandem or in RAID-0 have a .80 * .80 = .64 = 64% chance of surviving 3 years. These are fake numbers but you see how it works.

[Ozkar]

I can't remember from stats class but I think you multiply the odds to get cumulative in-series odds. Like if a single Raptor has an 80% chance of surviving 3 years, Raptors in tandem or in RAID-0 have a .80 * .80 = .64 = 64% chance of surviving 3 years. These are fake numbers but you see how it works.

I was thinking the same thing, but then I saw this article which says that if you have 2 drives in RAID 0, the Mean Time To Failure (MTTF) is cut in half. They have a nice graph showing that if the MTTF of 1 drive is 11.4 years, then 2 drives in RAID 0 have a MTTF of 5.7 years. The formula is:

MTTF(RAID0) = MTTF(Disk) / (# of disks)

[hyperslug]

FYI, someone over at SR says you'll hit the bus limit if you RAID 0 two Raptors. This is with the new, non-Beta sample they just tested, and it runs faster (and louder) than the previous 2nd gen sample.

[Ozkar]

FYI, someone over at SR says you'll hit the bus limit if you RAID 0 two Raptors. This is with the new, non-Beta sample they just tested, and it runs faster (and louder) than the previous 2nd gen sample.

I think that is true if you use a RAID controller card, because of the PCI bus limit, but what about my Intel Motherboard D875PBZ, which has integrated RAID support?

[HammerSandwich]

I think that is true if you use a RAID controller card, because of the PCI bus limit, but what about my Intel Motherboard D875PBZ, which has integrated RAID support?

While the ICH5R removes RAID from the PCI bus, there remains a 266 MB/sec bottleneck between the ICH and the MCH (aka northbridge). The ICH has 2 SATA, 2 PATA, USB2.0, PCI, etc. as seen here.

[Putz]

RAID-0 will only help your computer boot a few seconds faster, and increase performance a bit if you work with a lot of large media files (Photoshop, CAD, video). If you would really like snappier performance than 1 Raptor will provide, consider setting two Raptors up independently. Separate your O/S from page file, your apps from data/scratch space, etc. That will net a greater improvement, especially if they're on seperate channels (which all SATAs are). Many people at StorageReview will agree.

But yeah, first try one Raptor. You might find that you'll be happy enough with that alone, and then you'll have saved yourself a lot of money. Also, I think the newer Raptors with FDB are supposed to have 37GB/platter, not 36GB.

[chylld]

I don't know about you guys but I personally wouldn't ever touch RAID 0 (that's my opinion of what I would do). I have a lot of important stuff on my computer, and even though I take care of my HDD (modified case to force airflow over hdd, keeping temps under 40C) the risk of data loss is simply not worth taking.

In fact, next week I'm going to buy another HDD to run RAID 1, which will still give me twice the read performance, albeit without any write performance boost.

I've experienced a hard drive failure before (in my laptop) and it is not a nice thing at all. Imagine losing many years of hard work just like *that*.

I should note that I actually do use a lot of disk-intensive utilities - I do a lot of video editing etc., but I simply cannot justify a simple speed increase with twice the rate of failure.

[dasman]

RAID-0 will only help your computer boot a few seconds faster, and increase performance a bit if you work with a lot of large media files (Photoshop, CAD, video

Exactly. On my personal machine I have (4) drives (7200.7's, recently suspended) on a 4 channel card. They're set up as 2 RAID 0's -- first is OS & application files. second raid is page file & my files.

RAID is a huge benefit when working with large chunks of video, large photoshop files, etc. If the application does alot of writing to disk, you'll also come out ahead. If what you're working with can typically be held in RAM without paging to disk, then you won't see much advantage to RAID except when booting and loading stuff.

As for backing up -- I've never had a RAID go down (~5 years), but then I swap out the drives every 2 years. I have the OS/boot raid ghosted and my daily backup is to an external HD. I archive to DVD.

At the office, our server has (5) drives for data -- (4) in a RAID 5 with one as a hot spare if the raid goes down. Again, we've never lost the raid, but we swap the drives out every two years there as well (that's what gave me the idea to do the same at home).

If you work with big enough files, then raid is worth the $$. Otherwise, raid is a status symbol. Also, I would never use bleeding edge hardware (ie, Raptor) in a RAID 0 -- reliability of the hardware is key. The speed comes from the multiple drives, each on it's own channel.

Dave

PS On a PC, If you haven't maxed out your motherboard RAM, then you don't need RAID... yet.