Ok well just a few points.
1. That machine is way way too low spec. XP can run fine on that spec without doing anything tooo demanding but yeah, its not exactly high spec for doing anything demanding with.
2. USB transfer requires CPU use. To use it constantly as a hard drive is going to be constantly using and draining CPU cycles. To have it reading and writing to multiple drives is going to be using constant CPU cycles continually for the data transfer to each drive.
Compare this to say an IDE drive that have DMA (
http://en.wikipedia.org/wiki/Direct_memory_access) and and your computer can basically just say "transfer this file to here" and then the CPU stops having to do all the work and the file is just transfered via the hardware. With USB on the other hand the CPU is required to read and write each Byte from the source to destination. That's why you'll notice your machine slows significantly when doing file operations on your USB drives whereas if you are using say three IDE drives and you transfer from drive B to C (both of which aren't the OS drive) you wont notice much of a system slow down.
3. Raid normally works similarly to DMA in terms of your computer says to the Raid controller "write this file" and the controller then does all the work and copies it between destinations, splits it, does whatever else and writes it to the appropriate destination with however many copies or splits etc that it needs.
With a software raid however your OS is having to calculate each time which hard drive it is going to write which bit of data to. Add in the fact that they are USB drives and it is having to use CPU cycles to read each byte of data, then more cycles to chop the file and work out which drive it is going to have to write to, then more cycles ontop of that to write that file to each of those drives. Presuming it does some kind of file verification after it writes this will then require more CPU cycles to do.
A windows machine slowing down with use to be honest though isn't a surprise. As many a joke says - Windows can stay up and running fine, all you have to do is just not use it! lol.
As soon as you start using windows, installing things on it, etc. it always slows down!
A 600Mhz machine is nowhere near fast enough to handle all this smoothly as well as being used. If it was a stand alone server it could but would still not be that overly fast.
For a Software Raid you'll want quite a bit of RAM and quite a fast CPU. For a Software Raid using USB you'll DEFINITELY want a fast CPU and alot of RAM.
The above info is all pretty objective information, it can be confirmed anywhere on the internet pretty easily.
On a totally subjective note that's just me:
I'm fried - my external Lacie Big Disk is totally kaput. It's got 3 interfaces (USB, Firewire1 and Firewire2). The USB has packed in on me and so the drives are totally not readable nor any of the content on it which I hadn't backed up (This was my backup, unfortunately the original is gone already!
. I figured if I use the Firewire connection it'll bypass the USB controller and should work fine - what'd you know, no joy. Looks like the board is kaplow or something
I hate USB drives and think they're probably as reliable as a good old floppy disk!
Your formatting sounds like a good idea. Especially on a server, the less you load onto it the better so it can just focus on it's main purpose.
I just did mine and it runs sooooo smoothly and fast it's incredible, hardly feels at all like the slow blugening monster it was before the format.
I'm just trying to refrain now from installing anything on it!
Dont want to risk upsetting the Windows Monster!
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Topic: Raid 5 Slowdown? (Read 6555 times)