Does having multiple partitions slow down RAID?

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I have two WD 100GB (8mb cache) in a Stripe 0 RAID using my motherboard's onboard Promise controller. Normally, I just make one partition, but yesterday I decided to make two even sized ones. But I noticed things seemed a little slow. So I tested with Sisoft Sandra and it's transferring way slower than it should be. I assumed partitions wouldn't have an impact on the effeciency of RAID. Was I wrong, or is it something else causing the slowdown?


Windows 2003 Server
Gigabyte GA-8HIXP
Pentium 2.4b
1024mb PC1066 Rdram
 
It shouldn't have any more effect on raid than having two partions on one device.

If you've got your system drive on one partition and the drive being tested on another partition, you could be generating a whole lot of head seeking which will kill performance.
 
My system is on one partition (C), and storage is on the other (X). I've tested both of the drives, and the results vary on each run.

I've been using RAID from the very beginning with this system. However, I'm considering just running the drives seperately. I use my computer as a general desktop. Sometimes I work with big files when I'm encoding videos, etc. Do you think I'll notice much difference if I give up RAID? I'm just trying to figure out the pros and cons of not using it.
 
Using multiple partitions on one drive always lowers performance.

RAID0 = treating multiple drives as one, therefore performance will be reduced.
 
But isn't the point of RAID 0 to sustain higher (linear) transfer rates (after all the seeking is done *two* (or more) HDDs deliver the data instead of just one)?
 
[maven said:
]But isn't the point of RAID 0 to sustain higher (linear) transfer rates (after all the seeking is done *two* (or more) HDDs deliver the data instead of just one)?
Click to expand...

Yes. By striping across two disks with two controllers, you thoretically double your bandwidth as well as increasing the logical size of the drive. So instead of writing one file at the speed of one disk/one interface, you shove two halves of the file down separate controllers to two separate disks, doing the read/write job in half the time.

That's the basic idea, but of course there are a lot of other variables that can affect your speed, such as block sizes, caching, parity updates (on higher levels of RAID)

Multiple paritions *shouldn't* be any slower, but depending on the layout of the disc platters and heads, you might find that you're actually getting contention by trying to run two partitions at the same time that are both being served by the same platter/head.
 
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