Getting slower speed after installing RAID 0 PCI Card on drive

Hi, I have installed windows vista Home Premium x32 on my machine and I want to use it with my 4 500GB hard drives to create a RAID 0 array of 2 TB. And I have I set it up with the auto configuration on my machine, but the thing is like when I was getting 100MB/s I/O rate while transferring any content, but at the same end currently I am getting 10 MB/s and which is actually 10x decrease!

Any idea what could be the problem with the card ?

I was also having this kind of problem with the system speed and I found that it was actually because of the controller rather software’s that we used while configuring the RAID drives.

Thus according to me you should try to reconfigure the device and as I have done the same thing an it was resolved easily.

If you want to run you RAID-0 device with full speed, you must have to have partitions from distinct disks.
Besides,placing the two halves of the mirror on the similar disk fails to deliver you any safety whatsoever against disk failure.

which kind of drives you have made in the while creating RAID arrays, because see there are two types of drives such as either matched or unmatched. And off course they both have their own advantages and disadvantages. Thus I would like to say if you have made matched drives then you should try to make them unmatched and see whether you are getting any difference in the speed of your device?

The advantages of matched drives are additional of a value-economic stand. The array is only going to be as fast as the slowest drive. extra factors are rational, not physical (misaligned stripe array).

I am not sure about this but it might be possible that the card that you are using might have been corrupted. Have you tried is it working perfectly or not, I mean to say you should try to re-attach the card and then see what happens.

Or else you can simply reinstall the drivers that you must have installed in your machine. because sometimes that causes the main problem when they get either corrupted or some files are missing from the program files.

You can download the most recent drivers from its respective website.

It might be possible that the PCI port on your motherboard is quite slower and you might be getting slower speed because of that only.

Thus according to me you should try to attach the card to another PCI slot.

I have heard that chunk size (stripe size) influence the speed of my RAID-0 devices, is it true? And if so then how is it possible any idea?

yeah that’s quite concerning things but I would like to tell you about the same The chunk size is the amount of data adjacent on the essential device that is also adjacent on the physical device. In this , "chunk" and "stripe" refer to the similar thing: what is commonly called the "stripe" in other RAID documentation is called the "chunk" in the MD man pages. Stripes or chunks apply only to RAID 0, 4 and 5, The stripe size affects both read and write latency that’s “delay” and throughput bandwidth, and contention among sovereign operations in other words ability to simultaneously service overlapping I/O requests.

I found that using a 256k stripe gives much better performance.

by means of more than one controller to perform disk access in similar will get better performance. nevertheless, the genuine enhancement relies on your actual configuration. For instance , it has been reported that a single 4.5GB Cheetah attached to an Adaptec 2940UW can achieve a rate of 14MB/sec without using RAID. Installing two disks on one controller, and using a RAID-0 configuration results in a calculated performance of 30 MB/sec.

Note that the 2940UW controller is an "Ultra-Wide" SCSI controller, capable of a academically burst rate of 45MB/sec, and so the over measurements are not astonishing. However, a slower controller joined to two fast disks would be the tailback. Note also, that most out-board SCSI enclosure e.g. the kind with hot-pluggable trays, cannot be run at the 45MB/sec rate, owing cabling and electrical noise troubles.