Wondering about raids---need mem refresh
I have sense forgotten a little about raids and am wondering if there are any raids where you can plug 3 or more drives into it and have it act like a raid 0, just with even more speed.
Most motherboards limit you to only like raid 1 and 0, correct?
Most motherboards limit you to only like raid 1 and 0, correct?
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Is raid 1 going to perform better than raid 5? Or when and by how much? I thought that if you have 3 drives in raid 5 it would be like 2 in raid 0 with 1 backup like raid 1. Am I correct? I want the absolute best performance, but would like some security.
Usually raid 5 is going to out preform raid 1. You are correct in the way raid 5 preforms... Don't forget that for best results use drives that are the same make and model and size.
Also if you don't use drives of the same size the array will only be as big as the smallest drive. for example 30gb 60gb 80gb in raid 5 is going to be 30+30+30 for a tot of 90gb with 30gb and 50gb unused and unavailabe to be used on the other 2 drives.
Also, JMO, after 3 years using both raid 0 and 1 I have come to the conclusion that raid is not worth the effort.
Raid 0 while definately faster sucks when one of your drives craps out... Even if you back up your data going trough the RMA process takes weeks and your array could be down for days.
Raid 1, great for redundancy but it is slow on the writes... It's really only good if you are backing up data that is not changed very much, as trying to use it for your OS and progys can cause laggs due to the extra time it takes to write data to both drives. I can see it for a server...
Raid 5, great IF you have the money for 4 or 5 drives, you really don't see the speed increase in raid 5 until you get a 32/66 or 64/66 true raid card that does real actual raid 5 like the 3ware cards or the LSI's then you can see benifits but it cost too much for me to buy 4 or 5 drives.... Might try it with some 20gb'ers or something off ebay but can't forget the draw on the PSU... Most PSUs won't supply that kind of power and still have enough for the rest of the system...
In short, they are fun to play with but all in all... you really, really don't need it...
"g"
Not sure what your question is realy but I'll try and answer what I think your asking...
There are several companies that manufacture both SCSI and IDE raid cards.
Promise, Highpoint, 3ware, LSI are just a few.
Some cards are limited in the types of raid that they can run and are not really true raid cards. They emulate a raid through software, kind of like the software raid that can be set up through XP Pro. There are cards that have on board RISK or other type of prcessors that do all of the data processing involved in the RAID, seperate from your CPU. The IDE is baised on the SCSI idea but is not exacly the same. The expensive cards come in either 32/66, 64/33 or 64/66... Unless you have 64/66 slots in your computer, which most reagular systems do not, you won't have any use for the 64bit cards...
Most of the raid controlers on mother boards are a cheap version of what ever particular company has made a deal with the mob manufature like promise and highpoint for example. These usually are limited to raid 0 and raid 1 with a few boasting the ability to do raid 5 but because its software generated raid 5 will usually not show any performance increase over just regular drives not raided...
At this point I really don't know what more I can add, there is a plethra of info on the web about raids which go form raid 0 to raid 50. Like I suggested if your just playing around that's all good, but for everyday use on the average machine its a waste of time and money... IMHO
Hope this helps,
"g"
So... are most raid cards going to be the same in performance wise? Or do some give a cheaper "gets the job done" point of view? I like the best.
raid-5 will never outperform raid-0 or raid-1 with equal number of disks. Its the cheapest and sliowest way to get redundancy. The writes are usually horrid. As in.... a 4 or 5 drive setup is slower then a single 5 or 6 year old ide drive on the writes.
I have not seen a non sata raid setup on a modern motherboard that also didnt support more then two drives in raid-0. You get two per channel just like normal pata raid.
And as far as wondering what to avoid if you setup a raid-0 array??? Easy. Not backing up. You lose the entire array if any single drive fails. So keep anything important you can't afford to lose backed up.
Tex
Now, is there some raid that adds performance like raid 0, but also can add a tad bit of security? I don't have the money or will to have raid 0+1, the best setup I am thinking about would have 1 drive backup security with all the others just adding together. so... 4 250gigabyte harddrives would give 750 and one could crash and stuff would still work good, that would be ideal, just somebackup, but mostly performance.
Raid-10 (0+1 or 1 + 0 is basicaly the same) is the best speed, performance etc... with redundancy. If you don't want to play that game make two seperate raid-0's and use one to back up the important data from one to but don't mirror it. You don't need to store mp3's and crap on raid anyway.
I have big scsi raid-0 arrays with 5 to 8 disks on multiple dual cpu machines with 64/66 or pci-x slots but... I also back the servers up to each other or to big ide drives across a gigabit network. I have probably built and tuned more ide and scsi raid arrays both professionally and of my own in the last few years then most people will do in a lifetime. I buy and sell scsi disks and controllers as a side line of sorts. And the rule with raid-0 is you never store anything there you can't afford to lose. So back it up dude.
Cheers
Tex
Your limited more by how fast the drives are not how many per channel. With new state of the art drives you runout of bandwidth long before you run out of the ability to attach physical drives. You can physically attach probabvly just under 30 to that controller. But with the the fastest state of the art drives you want two per channel for a total of four. With fast but more reasoanbble priced drives figure three per channel or six total. If your bvuying older slower used drives you can cram a bunch on.
Yes I can post tons on benchmarks from Elite 1600's or Enterprise 1600's either one. I have bought and sold maybe 30 in the last 24 months.
Latest toy is the newer lsi 320-2x. It's cpu is tons faster and it can handle a gb of ddr cache onboard. Mine has 512mb of pc3200 ddr on it right now. The benchs from it are breathtaking to say the least. They will knock your socks off and fold them for you.
Tex
Tex
So, are you saying that I shouldn't go this route then? What do you think the best route would be then? They are only 32bit as of now. All the other stuff I think has already been said somewhere.