Equinox

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Nov 4, 2002
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Hi everyone.

I'm new to this forum so I would like to say hello and dive straight in with a request for advice.

I have recently created the following RAID setup on my Abit KX7 333R mobo:

Channel 1. 2x WD ATA100 7200 100Gb HDD's, 64k block size, RAID 0.
Channel 2. 2x IBM ATA100 7200 120Gb HDD's, 32k block size, RAID 0.

After monitoring the performance of this setup for the past week I have concluded that it performs way below what I had expected.

Sandra 2001 benchmarks both drives only slightly higher than a single 28Gb 7200 ATA66 HDD.

Is the poor performance possibly due to incorrect block size? Or could it simply be that the drives are wrongly placed on the IDE channels?

If the latter is true then is it possible for me to reposition the drives without damaging the array?

Thanks.

Equinox.
 

HammerBot

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Jun 27, 2002
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I think it would be better to place the harddrives in this way:

Channel 1: Master WD drive 1, Slave IBM drive 1
Channel 2: Master WD drive 2, Slave IBM drive 2

In this way, when accessing the WD or the IBM array, each harddisk has the full bandwidth of each channel.

The stripesize and clustersize often has a significant influence on the performance. What filesystem and clustersize are you using? The default clustersize of NTFS is 4Kb which appears to be the worse for RAID0.
In general a large stripesize is preferred if you use the drive for large files like video streaming etc. For mainstream (office, gaming etc.) a stripesize of 8-32 Kb is a common choise.
Regarding the clustersize, I dont have any rule of thumb that in general appear to apply. I suggest you try different combinations and benchmark with both large and small files.

If you dont change the stripsize, I think it is possible to reposition the drives without damaging the array. Obviosly you have to enter the RAID bios and specify the new drive locations.

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