4x640gb - RAID 10 vs. RAID 0 - What am I missing out on?

JoelKatz

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Quote from: st4rdust on July 12, 2011, 11:52:51 PM

I was really hoping to get an idea of how much of a performance boost that my four drives in a RAID 0 would experience instead of having just two in a RAID 0.

Okay, let's try it this way:

Four drives in RAID 0:
Read is about four times the speed of a single drive.
Write is about four times the speed of a single drive.

Two drives in RAID 0:
Read is 2x
Write is 2x

Four drives in RAID 10:
Read is 4X (we can read from all drives at full speed)
Write is 2X (since each byte is written twice)

Wuked

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Raid-0 is only for use in casual use when backups don't matter...

I've got a raid-0 of 2 x 240GB SSD drives that read at 1000 mb/sec, but it's not usable in production Sad

NetTecture

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Rarely a problem unless you use SSD or just load / copy one file. I have a RAID 10 of 8 Velociraptors and I overload the discs regularly - like many times per day. Because the server runs hyper-v and many machiens read different sectors so the heads ahve to move like mad.

Disc speed is only in a very simple trivial edge case limited by bandwidth, normally it is IOPS that is the limit in heavier use.

That said, SSD rock Wink

A 120gb Vertex 3 + that as Raid 5 combines fast disc with good effective storage.

Sideways

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Quote from: NetTecture on July 13, 2011, 12:25:36 AM

Simple math. 4 drives in raid 0 have twice the io erformacne of 2.

As long as your controller has the bandwidth..

NetTecture

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Simple math. 4 drives in raid 0 have twice the io erformacne of 2.

st4rdust

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Thanks for the responses, although I'm already familiar with the different RAID levels. Also, I'm not concerned with the increased risk of failure per drive. As I said in my main post, this is on a gaming PC so losing all data wouldn't be especially heartbreaking as I simply reinstall what I need to and go on with my day.

I was really hoping to get an idea of how much of a performance boost that my four drives in a RAID 0 would experience instead of having just two in a RAID 0.

max in montreal

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The only problem when striping, the more drives you use, the more chance of failure. Using 2 hard drives doubles the failure rate over using one drive. Using 10 hard drives will make it extremely fast, but if one of those drives fails, all your data is gone.

Imagine telling 10 different people about different parts to finding a treasure. if one of those people get killed there is no way to get the treasure...YARRRRRRRRRRRRRRRRRRRRRRRR!

max in montreal

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ok, there is mirror, and there is stripe.

mirror = 2 drives with the exact same thing on both drives. if one drive fails its ok you have an exact copy on the other.
stripe = 2 drives, 1/2 the info on each...Its like having one employee do all the work( this is a single drive without any raid) or having 2 employees in a company share the work. When they are sharing the work the work gets done a lot faster. Stripe is much faster but if you only have a stripe setup, if you lose one drive then all your data is gone.

mirror is raid 1 stripe is raid 0. For each of them the minimum amount of hard drives you can use is 2.

Raid 10 is using raid 1 and raid 0 at the same time. With 4 hard drives A,B,C and D, A would have half the data, B would have the other half. C would be a copy of A and D would be a copy of B.

Hardware raid is faster than software raid.

Hope this helped.

Max

Oldminer

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I went for a RAID 0 setup using raptor drives a few years ago and the performance difference blew me away. I've never looked back. Some months ago I replaced the raptors with 2 x SSD drives, in RAID 0, and the speed increase is phenomenal. Grin

st4rdust

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When I set up this PC, I had four WD 640gb SATAII drives which I intended to use in a RAID 0. Upon installation, I found that the motherboard RAID controller wouldn't allow this many drives in a RAID 0. I had the option of a RAID 5, but I didn't think this would be appropriate for what would mostly be a gaming PC. It also gave me the option to run three drives in RAID 0, but not wanting to waste the fourth drive, I wound up striping two of the drives, then mirroring them with the other two. This setup never overwhelmed me with its performance, and I often wonder what I missed by not setting up my originally planned RAID 0. Can anyone with knowledge of RAID systems speculate on what advantage, if any, my four drives in a RAID 0 would have over my current setup?

Topic: 4x640gb - RAID 10 vs. RAID 0 - What am I missing out on? (Read 3366 times)