What stripe size should I use on my system for raid 0?

windie

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I have 2x250gb Seagate Sata II drives, have them on raid 0 on a Gigabyte P35 DS3R motherboard. I have vista installed (32 bit) and my system is only going to be used for games and office tasks.

What would an ideal stripe size be? The default (which was the highest it could go) was 128k so I used that. But would a lower stripe size benefit for vista, gaming and office task usage? Any suggestions would be appreciated, thanks
 

prolfe

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Quick Google search indicates that the stripe size should generally be as big as possible. Files under the stripe size do not get split, which means (in your case) that any file less than 128K will not see a speed boost from the RAID. Files larger than the stripe size get split in multiples of the stripe, so the smaller the stripe size, the more blocks the files get broken into. Obviously the more blocks there are, the more overhead there is to reconstruct the file.

Hope this helps!
 

windie

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thanks. I did google, and got some conflicted results. One was also that for normal windows and games, probably use a smaller stripe size, while for video editing for eg, 128k would be good.
So thats what im kinda confused, for sure larger files benefit from a larger stripe size. But do smaller files benefit from smaller stripe size (because windows I believe has lots of smaller files [comepared to big], games too vary from each other)?
hmm, ill see what else i can find.
 

prolfe

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Well, as I said, any file smaller than the stripesize will not benefit from the RAID. 128K is a pretty small file; I'm inclined to believe that you would be in good shape with 128.
 

windie

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lol, well i thought 128 was considered big. But have read that since this is an onboard raid thing, that is why its limited to 128k, but doesnt mean its big :). my bad
 

P0110X

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First of all, stripe size doesn't stand for file size. It's arrangement of data through different hard disks interpreted as one hard disk, by software layer (operating system).

I used RAID0 for almost a year, until one hard disk damaged (and it was new, Samsung, so no more samsung hard disks for me hehe)

I recommend you to have at least three partitions:
1. boot and swap: its size should be memory x 1.5 at least, with NTFS block size default. The first part of any disk is 40% faster than the last part, so place your swap file in this partition.
2. OS (vista in your case): its NTFS block size should be the default too
3. data: since you have big files, I recommend the highest possible for NTFS block size.

Why I'm talking about ntfs block size? it's pretty close to stripe size.

From my experience, 64kbytes stripe size made speakers glitch when playing mp3s, I think because bigger stripe sizes means more data to load. That's why I used 16kbytes for stripe size and ntfs default block size (4kbytes).

Remember that RAID0 timings searching data are slower than a normal hard disk. This means if your search access time is 8ms, with two hard disks in raid0 will be 14-16ms!. You can prove this with Sandra software.

If your ntfs block size is, for example, 4 kbytes, your stripe size, for two hard disks, should be 8, 16, 32... kbytes. Why? If you have to save 64kbytes and your stripe size is 8kbytes and the ntfs block size is 4kbytes, then the raid controller will write this:

1. two pieces of 4kbytes in one hard disk (because the stripe size is 8 kbytes and the ntfs block size is 4kbytes)
2. the same with the other hard disk
(at this point, 16kbytes of data have been written)
3. and so on...
check this at http://www.adriansrojakpot.com/Speed_Demonz/IDE_RAID/RAID_03.htm a great visual way to understand striping (i googled it a couple of minutes ago :D )

As you can see, RAID0 does not mean that the information in the hard disks will be in the same place, with one part of a block in one hard disk and the other part in the another.

With bigger stripe sizes, storage will be reduced also.

I hope this helps. ask whatever you want :D