RAID 0 , RAID 1, or RAID 0+1, which is best and most convenient for a joe average computer user?

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Technosnob

Junior Member
Dec 26, 2000
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Wiz, I have never experimented with SCSI drives, but what I see as far as posted benchmarks, is the IDE raids perform just as well as the SCSI. Two IDE drives and an IDE controller card cost less than a single, relatively decent size, SCSI drive. If you have your average gamer trying to gain some drive performance, would your SCSI experience still have you recommend it as the solution? You also make a good point on the channels, you take a real performance hit if you combine drives on the same cable. Always use seperate channels. ITISU, I also agree that you should look for the performance bottleneck. Most people would be better served in buying additional RAM as opposed to a RAID solution. Then there are the crazy people like me who just want to climb the RAID mountain because it's there.
 

Wiz

Diamond Member
Feb 5, 2000
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Technosnob,
heheheheh... I guess it's 'true' that most people don't really need much performance at all.
You should play with some Ultra 160 10k rpm or even the new 15k rpm drives and then come back and talk about the performance of IDE. There really is no contest whatsoever.
But until then the performance of Ultra DMA 66 and 100 drives really are not bad, however they are not 'just as good' as scsi. (maybe scsi2)
Just my own not so humble opinion (JMONSHO)
Also, I don't believe (I could be mistaken) the IDE raid cards give you two separate independant channels of raid. Whenever you are trying to send all your data simultaneously from / to the drives if you can't do it simultaneously over two independent raid busses then you are really defeating your purpose, if that is performance.
SCSI drives are also wonderful at multitasking, while IDE don't do that very well.
When looking at the benchmarking be sure you are comparing the same years technology. For instance if you compare a RAID01 setup between ATA100 and Ultra SCSI2 then it may be about even, but the same setup with Ultra160 SCSI3 drives / controllers would be much faster.
You are correct that for the common person who can't lay down $1500 just for their disk system they should go ATA66 or 100.
Personally for my own workstation I chose the Ultra 160 controller and the 36 gig Quantum Ultra 160 scsi drive at 10,000rpm. No muss no fuss!
My servers run RAID5 with 64 megs cache ram on the controller - but they get a lot of users per second.
 

RoadRuner

Banned
Oct 4, 2000
765
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For data security, raid 0+1 simply rules. Write io is not limited by parity, and a double-disk failure or more, can occur if the conditions are right, your raid will still function. Also rebuilds are quicker.

Raid 5 of course, you get much more data storage with n-1 raid 5, however, disk writes must be spread across many busy drives, and with parity, will result in MUCH slower write access, and similar read access.

I've got both raid 0+1, and raid 5 at work, including one raidweb.com which uses ide ibm 75gxp (8 75 giggers). It's pretty fast. only about $9K for 500 gigs of redundant storage. The raidweb is plug n play, and sports a ultra2-lvd external connection for compability with various platforms.


:)

 

Wiz

Diamond Member
Feb 5, 2000
6,459
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That raidweb is a cool setup.
You can build your own slightly less powerful but still good raid5 with a $600 adaptec
controller and a $150 cable and 5 to 10 drives.
I have found with raid5 the writes suffer greatly, but reads are only slightly slower than from a single drive. In a web application serving environment it's not an issue as many things can be (and must be) read and delivered simultaneously.
The 64 megs of cache really helps too.
The greatest feature is that I get to sleep at night not worrying that a single drive failure will put me out of business.
I can actually go on vacation for 4 or 5 days and not think about it too much.
3 or 4 drives die, I just go in and replace or rebuild. Not a problem.
Sometimes I can even do it remotely from the laptop in the hotel room ;)
Peace of mind is the best reason to use RAID.
Performance? - I feel if you just get a really good 10k or 15k rpm drive you will have all the performance you personally need. If it doesn't need data redundancy then spend your money on the stuff that makes you happier, a good vid card or monitor for instance.
Man, that's about 2 1/2 cents worth.
 

Technosnob

Junior Member
Dec 26, 2000
24
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Wiz, my phrasing was a little sideways in my previous post. I realize that a SCSI RAID will blow away an IDE raid (for 5x the cost) but the benchmarks I've seen posted have the IDE raid as fast or faster than the single SCSI 160 solution for about half the cost. If I were a site manager or IT manager then the SCSI raid is the truth and the light. But for us average Joes on the street, is worth the extra cost for the SCSI controller and the single SCSI drive vs the IDE raid 0 solution?
 

Wiz

Diamond Member
Feb 5, 2000
6,459
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hmmm... I definitely agree with what you say about average folks just needing IDE and that's good enough - ne sense spending the extra $$ on SCSI raid for home use.
But I doubt any benchmarks showing an IDE anything to be faster than a single U160 scsi.
You know how benchmarks can be easily slanted depending on what is tested and how.
The U160 controller is so much smarter about disk IO that I would bet a 160 drive could easily outperform anything maybe short of a 4 disk ATA100 setup on two channels, striped mirrored set. Even then, there are just some things scsi does better, like instead of saying 'Go get the next 100 blocks' like the IDE would the scsi conroller says 'go get blocks 50 - 80' because those are all that are really needed.
Of course there are better Disk IO solutions out there than U160 scsi, but they are expensive.