Internal Raid 0 - What rate can I expect?

If I set up a software Raid 0 (using Disk Utility) across 4 internal drives in an older Mac Pro (2007 Woodcrest), what data rate can I reliably expect?

What is largest individual drive I'm allowed to use in this configuration?

I'll backup nightly to an external drive (using Carbon Copy Cloner).

I'll move my startup disk to an external firewire drive.

Thanks!

Kona has a free utility to test the speed of Raid drives.
I couldn't find it quick to link, but it should be on the Kona web page.




Tom Sanders Wrote:
-------------------------------------------------------
> If I set up a software Raid 0 (using Disk Utility)
> across 4 internal drives in an older Mac Pro (2007
> Woodcrest), what data rate can I reliably expect?
>
>
> What is largest individual drive I'm allowed to
> use in this configuration?
>
> I'll backup nightly to an external drive (using
> Carbon Copy Cloner).
>
> I'll move my startup disk to an external firewire
> drive.
>
> Thanks!

I use to get somewhere around 135-145 on both read/write on a 3 drive Raid 0 via disk utility. This was with 3 750gb 7200 Seagate Barracuda drives. When they were empty I seem to remember getting about 160 on the read, but write speeds stayed pretty consistent.

I just did a test with the AJA tester and with 2 seagate 1.5TB drives as Raid 0 with apple disk utility I got 220 MB/s write and 230 MB/s read.
This is on a 2006 mac pro dula core 2.0 Ghz.