TechSpot

Anyone explain RAID?

By henrychieng
Mar 12, 2002
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  1. Any expert here know how to use on board raid? I know that u must use identical hdd for raid! But i have AS40G Quantum , which is hard for me to get another one at the moment!

    Anyone tried raid with diff brand but identical 40G for instance? Pls help! Thx!
  2. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

    First of all you don't HAVE to have identical hard drives to raid them together, it is simply recommended. You may experience problems though when using two different hard drives, you'll just have to try it and see. I would try to get a second hard drive from the same manufactorer as the one you have now. You can have hard drives of different capacities also, but you will lose the space on the larger one.

    For instance if you have a 30 and a 60 gig Raided together then you will only have 60 gig of hard drive space. You lose the extra 30 gig that were on the 60 gig hard drive.

    If you have any questions on the raiding process just ask and I can try my best to help as I succeeded in raiding two IBM Deskstar's my first time! :)
    1 person likes this.
  3. boeingfixer

    boeingfixer TS Rookie Posts: 1,245

    Hey henrychieng,

    I too have just finished a RAID setup with two IBM Deskstar 40 gig drives.

    SuperCheetah is correct, the RAID will be only as big as the smallest drive and you will loose the remaining space, meaning that if you had a 60 and 40, you would have 80 total. The other 20 is gone forever (or until you reformat and take the RAID out of the picture).

    As to your drive, I have seen several of these on ebay in the $80-100 range. This was one of the drives I was looking for before I settled for the IBM's. Try ebay first. I actually bought the 2 IBM's for not much more than one at a retail store. They both work fine and are covered under warrenty.

    If you have anymore questions, let us know, we would be glad to answer them.
  4. Vehementi

    Vehementi TechSpot Paladin Posts: 3,199

    How many hard drives are you planning on putting in there?

    What array? RAID0, RAID1, RAID2...

    I've never used hard drives with such immense space, so I wouldn't know....

    Raiding two hard drives together is usually reserved for high access servers and such, why are you planning on going Raid?
  5. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70


    Hey thanks guys! In that case most likely i will source for 40G maxtor! ThD740X series! Seems like a good buy! Anyway, be trying out raid o on my MSIKT266 Pro Ru! Thanks guys!
  6. Didou

    Didou Bowtie extraordinair! Posts: 5,899

    What's RAID2 ?

    I've heard of RAID 0 + 1, where you strip & mirror at the same time ( with a total of 4 HDDs :eek ).
  7. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    Well...

    RAID LEVEL 2 uses its grouped together instead of bytes, and these are interleaved across multiple disks. Ths is a rare method.

    RAID LEVEL 3, simply uses 3 or more disks, and parity bits are stored in seperate, dedicated drives. It performs better.

    RAID LEVEL 4 is similar to Level 3, but manages disks independently rather than in unison.

    RAID LEVEL 5 is where data is striped across three or more drives for performance, and parity bits are used for fault tolerance. The parity bits from two drives are stored on a third drive.

    RAID LEVEL 6 is similar to RAID 5, but does two different parity computations or the same computation on overlapping subsets of the data. It totally kicks ***.

    RAID LEVEL 10 is a combination of RAID 1 and 0 (mirroring and striping).... This is VERY secure but uses a great number of disks.

    RAID arrays these days, in larger servers, are often hot swappable, meaning that disks can be removed and replaced whilst the server is up and running. The controllers for these arrays are large PCI devices, some of which are the size of motherboards.

    In my work, we use hot swappable RAID 5 arrays, which are probably the most common server solution. Servers having this kind of tech are usually SCSI only, have multiple CPUs (2, 4 or even 8 or 16) and have large amounts of RAM (1 or 2 GB of RAM or more....) These kinds of servers usually cost around £15,000 or more, which you can get a crappy flat in Scotland for.
  8. Arris

    Arris TS Evangelist Posts: 4,548   +95

    Crappy flats are more expensive in Aberdeen, they go for about 25 - 30K ;)

    I've never really felt the need to use raid...
    What benefits does it have for the home user and gamer?
  9. boeingfixer

    boeingfixer TS Rookie Posts: 1,245

    Hey Vehementi,

    Raid is a great way to get alittle extra performance out of two drives. Alot of the new boards have the ability to do raid 0 and 1 onboard with no special cards. I have the Giga-Byte GA-7DXR board with an onboard Promise controller and it was very easy to set up an array with it. It also gives you 8 channels to put devices on instead of the normal 4, preventing you from buying another card to take up another pci slot.
  10. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70

    can i ask, will there be a slight performace increase if u use raid o in my MSIKT266 Pro Ru mtb? Said like 10%? or 20%?

    I'm using XP1600 (unlock)but oc to Xp1900 with crucial 256mb! Using Quantum AS40G! Will i get another 10% increase in perf? Cheers!
  11. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

    Most raid 0 users will experience anywhere from a 20% all the way up to around 50% increase in performance depending on the system. So the answer to your question is yes, you should definitely see some quality improvement over your previous setup.

    I recommend running some test like HDTach or Sandra or Madonion's new benchmark PCMark both before and after you raid and see what the differences are.
     
  12. Didou

    Didou Bowtie extraordinair! Posts: 5,899

    It might be faster but there are negative sides to it for a normal user. If you use stripping, you can no longer just take one of your drives to put on a seperate PC, unless it also has RAID in which case you still have to move both of your drives. The other problem is Data loss since the information is being split to two channels. Might want to look into that first.
  13. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70


    20% to 50% WOW!:eek:

    Really want to get the hand of it (raid 0)! Tnx guys for reconfirming the facts! Now i must source for a cheaper hdd in some comp garage :p !Cheers dude!
  14. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

    It's what we're here for. If you need any more help with raid or anything else just let us know. I also must say thanks to Arris for that indepth look into the different types of Raid.

    Good luck on finding a good hard drive!!! :)
  15. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

  16. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70

  17. uncleel

    uncleel TS Rookie Posts: 1,145

    I politely disagree.We discussed this in the old forum from an article @ www.maximumpc.com Although theory suggest a raid 0 would approach the speeds of scsi, test results showed a 7200rpm hd was almost as fast. Maximumpc was even befudled & conducting more test.

    I'll quote these when I get some time.
  18. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70

    That's the beauty of forum and i like the way u disagree things man! :D

    If what u said is true, then i think i better save that couples of hundred for a nice meal or buy some gifts for my girlfrd! Haha!

    Anyway, glad that u point out coz i haven't buy the hdd yet! Btw, show us more facts man! Thx n cheers!
  19. Vehementi

    Vehementi TechSpot Paladin Posts: 3,199

    I'm not saying RAID is bad. It's great! I only don't use it because I'm too broke to buy another hard drive and RAID controller, and I've never used it before, and so I wouldn't know what I'm doing.
    20-50% is pretty drastic, it only speeds up hard drive access time, and sure if you do do splitting, games will run alot faster at the expense that half your data is on one drive while he other half is on a different one.
    I'll ask my instructor what array he's using in the room's server (I'm currently studying A+), as I'd really like to learn more about it.
    RAID is great for data backup too. Either RAID1 or 0 clones information and sends it to two drives, so if one fails you still got the other. Invaluable, simply invaluable.
  20. uncleel

    uncleel TS Rookie Posts: 1,145

    p.s. You don't need to bold quote everything!

    p.s. You don't need to bold quote everything!
  21. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

    I think raid has alot to do with the type of system you run. I've seen benchmarks showing that Raid increasing system performance by 50% and other benchmarks where, like was said before, the raid array actually slowed down the hard drives.

    If you don't have the money, then I personally would not save up the money and buy another hard drive. Personally I haven't noticed too big of an increase in performance from my raid array, but I believe I haven't optimized it yet, so I plan to get on that soon.

    Whenever I do get around to doing that, I'll run some benchmarks and post my results to give you a better indication of raid performance at least in my system. :)

    Also, when I reformat and rebuilt my raid array I plan on posting an indepth article on what I did and how I went about it, and ask others to explain their procedure also, so hopefully that will help some. I'll try to do this by next week hopefully! :)
  22. henrychieng

    henrychieng TS Rookie Topic Starter Posts: 70


    COOL! Hope to see ur review soon! By then i will decide to buy the extra hdd or may be change my vga or may be my casing! Very itchy hand to change someting! Haha! (May be there is this call iitchy hand sydrome for pc next time)! Cheers!
  23. SuperCheetah

    SuperCheetah TS Rookie Posts: 868

    Just found this article that does a good comparison of Raid 0 with 2 drives vs. Raid 0 with 4 drives and vs. a single drive.

    I caught some heat over this a while back and just wanted to show you guys where my justification for Raid speeding up a system by 20-50 percent comes from. It is only in certain areas and really not too noticeable for real-life usage. Still, this article does a good job comparing the setups and giving detailed benchmarks, and is worth a look.
  24. Phantasm66

    Phantasm66 TS Rookie Posts: 6,504   +6

    http://www.adaptec.com/worldwide/pr...tml?sess=no&prodkey=quick_explanation_of_raid



  25. Eric Legge

    Eric Legge TS Rookie Posts: 224

    There is a good articles on RAID at these websites -

    Tom's Hardware -

    IDE Training Course, Part 1: A Detailed Look at the Basics...
    http://www17.tomshardware.com/storage/02q3/020806/index.html

    IDE Training Course, Part 2: Performance and Data Security with RAID -

    http://www17.tomshardware.com/storage/02q3/020813/index.html


    IDE Training Course, Part 3: Using RAID -

    http://www.tomshardware.com/newsletter/vol2/33/raid.html

    Other sites -

    http://www.itp-journals.com/search/t0914.htm

    http://www.pcnetworkadvisor.com/

    If you want to read other articles on the subject, or tutorials on how to set up a RAID system, enter the word "RAID" with the quotation marks in a search engine such as http://www.google.com/.

    Eric,

    http://www.legge40.freeserve.co.uk/BuyerBeware.htm


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