Multiple I/O requests with SATA RAID vs controller type

I'm looking for information/experience regarding a particular aspect of performance. I apologize in advance, but this will be a bit long, as I'm looking for people's real-world experience with a specific situation.

A brief background first..

When it comes to RAID, my experience is 95%+ with SCSI drives on hardware RAID controllers. I currently run stand-alone SCSI drives in my desktop. One of the reasons I've liked using SCSI is that it offers better performance in certain situations compared with stand-alone IDE (from my personal experience).

For example, if I am running multiple applications, and also doing 2 or more large file transfers from one SCSI hard drive to the other, I can run my applications fine. When I've done this same thing with multiple stand-alone IDE hard drives, my applications will slow down and the OS will chug.

Similarly, when I'm doing even one drive-to-drive large data transfer on a non-RAID IDE box, and listening to MP3s, the MP3 may stutter. With stand-alone SCSI, I do not see that.



This brings me to the current situation.

I'm wanting to add more storage space, and I want added redundancy. Since SATA is so much cheaper than SCSI, and I'm on a smaller budget, I was considering using SATA drives in a RAID1 configuration.

Nowadays SATA has NCQ, which may help with the above performance situations over IDE drives. But, I'm wondering about a few things.

*Has anyone experienced the chugging/performance issues I described above on a SATA RAID configuration?
*How about with regards to true hardware RAID vs hardware-assisted software RAID? (hardware-assisted software RAID being aka fakeraid, firmware-based RAID, driver-based RAID. I am not considering pure-OS based software RAID).

I'd like to find out if I can save money by buying an add-in (PCI-E) hardware-assisted software RAID card, or if I would still need a true hardware controller to avoid the chugging performance. On one hand, RAID1 is not exactly processor intensive. On the other hand, the extra cache memory might at least help with performance. Then again, maybe SATA would chug in a situation like above no matter what.

For what it's worth, I currently run XP Pro/SP3. I do have a floppy drive for F6 installations. And, I've read a number of reviews/Google-searched/searched these forums, but can't find the information I'm looking for.

Thanks in advance for any real-world experience you can provide.