Time to play Devil's Advocate - Do we really need RAID in de

[BladeRunner 0]

Over the past few months I have seen an influx of motherboards designed for workstations and home PC's that contain on-board RAID controllers.

More and more motherboards are going to start offering this as an option.

So the question really is do we really need RAID or is it just another gimmick we really don't need?

With standard IDE HD's now at 7,200rpm, ATA-100 connection & up to 2MB cache.

With the multi FIFO abilities of standard IDE controllers (Like those on say an 815e chipset) does RAID really benefit the end user?

I don't mean 'Can my benchmark result go any higher' kind of benefit, I mean in the real-world, with real-world applications & games.

Lets not forget that RAID has laways been a SCSI option, designed for use in servers where fault-tollerance and the ability to multi-read from many disks at the same time is required.

When using an application on a standard workstation PC the standard controllers have no hassle if you have a nice specification HD to go with it.

 

This message is in no ways designed to start a major flame war or argument.

Let me end with: Discuss!

 

 

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PIII 800EB, ASUS CUSL2, 512MB PC100 RAM (Hyundai), Matrox G400MAX, SB Live! Value, Intel 10/100 NIC, Adaptec 2940UW, IBM 7200 ATA100 30GB HD, IBM 7200 ATA66 20GB HD, Pioneer 32x/6x SCSI DVD, Yamaha 4416 SCSI CD-RW, Iomega Zip 100 SCSI Internal, Iiyama Vision Master Pro 410.

Windows 2000 Only

[Bursar 0]

An interesting topic.

 

Just because motherboards are starting to have RAID controllers built in, doesn't mean that they are going to be used properly. For most people 1 (maybe 2) drives attached via IDE is plenty. If you starting getting beyond that, you are probably better off moving to SCSI where you can daisy chain a number of drives together.

 

Failing that, you can get 127 devices chained off of USB (IIRC), so get a USB external drive, and start stacking them up!

 

The other thing is cost. For RAID 5, you need at least 3 disks, and one of them is not usuable by the system, so that hacks a 1/3 off of the amount of space available.

 

In addition to that, you have the added cost of fitting 3 disks to system instead of 1 or maybe 2.

 

And after that... you have the education thing. It's all very well having loads of disks all setup in a nice fault tolerant system, but if you don't know how to setup the system to make best use of the RAID, then you might as well not bother in the first place.

 

So, at the end of the day, I reckon that RAID is fine for servers, and maybe for really highend workstations, but everything else probably wouldn't really see any difference.

 

(Edited for a typo)

 

[This message has been edited by Bursar (edited 13 October 2000).]

[Down8 0]

I see what you mean about RAID for the desktop being gimmicky.

 

But, the reason I would like RAID on my home computer [besides that I do run a server from it], is for the redundacy. The idea of never having to worry about crashing and losing all of my data is great. And, with IDE hardrives being so damn cheap right now, I think having RAID at home is not too unreasonable.

 

-bZj

[Silent-IQ 0]

well, am not sure what to say but i think that raid is pretty much something that like 90% of users at home dont need. with ATA100 you got all the speed you need for the time beeing. I think that raid is still something that is to be used on high end servers and users that really need fast HD trffic. so...the usual user should be very much satified with ATA100......i am if nothing else.. :=)

 

//Silent

[Ge0ph 0]

For the user that surfs the net, plays games, does checking on the computer, and such, raid is ridicules. However for the users that that treats their box like a finely tuned mescal car, raid is a nice thing to have on a board. IDE raid is a cheap way to start playing with raid and understanding it, but it’s just a matter of time before the real power user will want to move to SCSI.

[OLEerror 0]

Providing RAID controllers in desktop computers is a logical step. 98% will not use this technology, today. However, what home-user really needs a 1GHz processor? or 512 meg of RAM? or dual processors? Very few. Probably not even enough to be considered a market. But that is today. Look at the expansive growth of computers, and the dependency the public has formed for them.

 

Desktop computers started off as no more than a means of data entry and word processing. And no one would ever consider having one in a small business or (God forbid) actually have one in their home. Now, it is almost impossible to find a business without at least one (and most often several) computers chugging away endlessly. 50% of the American public is online. Home networks have become common.

 

With this type of growth in usage, and the number of common devices that are being re-designed to tie into a personal computer, the need for desktop systems that are hardly distinguishable from servers is on the horizon. It is the natural evolution of the beast.

 

Right now high speed, fault-tolerant storage is something for high-end computing. Tomorrow, your Grandmother will be complaining that she needs another hot-swapable drive to slap into her RAID 5 because she has filled her recipe volume up again. And we wouldn't want Grandma to be upset, would we?

[tristan777 0]

well... i dont think it's really needed. i've also heard it's not that really that much faster unless you have more than an affordable number of drives.

 

the raid controller was optional on my socket A mobo, and i decided not to get it. i dont think that i will be needing it until hard drives get reeeeal cheap. like dirt.

[DosFreak 2]

I call 75gb drivers for $600 dirt cheap. 150gb for around $1k sounds good to me!

[DocSilly 0]

First lets look at what RAID level most users will use ... RAID-0 cause they don't care about redundancy but love speed.

 

But what do you speed up with RAID-0 ? Sustained Transfer Rates ... and when will you take advantage of STR ? well, when you're transfering large amounts of data and that's when you're into video editing or something comparable. Games load a splitsecond faster but most won't be able to notice the difference.

 

Hmmm, so Sustained Transfer Rates ain't that important (in my eyes), so what is ?

Random Access and seek times, the faster the better!

And what gives you best of both ?

SCSI, 10K drives (or Cheetah X15 *drool*)!

 

Most users will use RAID-0 (with little overall improvement)... RAID-1 (mirroring) will be rarely used since it won't gain any performance and RAID-0+1 (needs 4 drives) is the highest those lil onboard controllers can provide, you can forget about RAID-5 or higher.

Another thing with RAID-0 ... you'll lose everything when one drive in the array dies ... so better have a good backup strategy.

 

RAID-5 is the sweet spot for RAID between performance and redundancy for most serious people (and the industrie), it's also available for IDE but those controllers cost a pretty penny (I think Ultra66 start at $300 and Ultra100 at $400).

 

I say that SCSI gives a much better performance boost over IDE-RAID ... but IDE offers more GB per $ for your downloads and pr0n collection ... SCSI costs more for less GB's ...

 

Conclusion: Gamers should chose SCSI (at least 10K drives) for ultimate performance when they can afford it, maybe paired with a large IDE drive for downloads/MP3/backup.

I guess the ultimate solution would be an Ultra160 RAID controller (with 128MB cache) and 3 Cheetah X15 in RAID-5 for ultimate performance and redundancy ... but this is only an option for those who have too much money to burn (hey YOU, you can also sponsor MY setup when you still have money to burn, pretty please ??)

 

IDE users with a RAID board should experiment (when they like to do that) but shouldn't hope for SCSI performance since the slow access/random seek times of the IDE drives will remain slow ... and they should work on a good backup strategy when they use RAID-0 (just in case).

 

If ya want more info from those who know a lot more than me, go to www.storagereview.com and check their bbs, there is much more than I can put in my reply here.

 

[This message has been edited by DocSilly (edited 15 October 2000).]

[DosFreak 2]

I'm seriously thinking about going SCSI. I do video work and I'd like to get into raid. But unfortunately SCSI drives are too expensive. BUT fibre channels drivers are not. Anyway since I have a CDR it's not like I need alot of space anyway. I'd say about 50g would do me good. Ultra160 50g hd. Time to go searchin'.

[tristan777 0]

600 dollars for a hard drive(s) isnt cheap. u know how much dirt i could get for 600 bucks? more than 75 gigs worth.

 

i'd rather just get a 30 gig ATA-100 drive for like 150 bucks and be done with it. i dont see the point in raid if all i do is game. and type an occassional report or something.

 

i'm not rich or loony so i'm not going to pay 4 million dollars for a Ultra-160 controller. i see ATA-100 as the next best thing. cheap drives, decent transfer rates, and controller is on my mobo.

[DocSilly 0]

Bursar

 

I have to correct some details:

Quote:

Failing that, you can get 127 devices chained off of USB (IIRC), so get a USB external drive, and start stacking them up!

That's correct but it won't do you any good with HDD's due to the very low bandwidth of USB. This "might" change a lil with USB2 which offers 400Mbit/s (80MByte/s) bandwidth but I really doubt it'll be used for HDD as an interface.

Quote:

For RAID 5, you need at least 3 disks, and one of them is not usuable by the system, so that hacks a 1/3 off of the amount of space available.

That's not correct for RAID-5, you're describing RAID 3 Array With Dedicated Parity Drive where one HDD is used for the Parity data only.

RAID-5 writes the Parity info over all drives. The advantage of RAID-5 is that performance is close to RAID-0 (with a good RAID card with plenty of cache) and redundancy is so good that any one drive can fail and be replaced and the system would rebuild itself.

 

More info on different RAID levels can be found here:

http://www.dell.com/us/en/biz/topics/vectors_1999-raid.htm

http://arstechnica.com/paedia/r/raid-1.html

[Bursar 0]

Doc: The comment about USB wasn't meant to imply that it was a high performance solution, just a way of chaining loads of drives together at a reasonable price.

 

The bit about RAID was my goof. You're right, you lose a 1/3 of the space, but it is across all drives, and not one drive that is dedicated to the job of storing parity.

 

I'll make sure my points clearer in future.