I don't know about your experiences guys, but RAID0 shows a marked improvement in performance in the right setup. Windows loads in what feels to be practically no time (by comparison to non-RAID0 using the same hdd), programs load quicker, game level load times are nonexistent, etc. True that video capture / editing / rendering runs quicker too.
Now that I've said this, RAID0 when used with a PCI-based controller on Via-chipset based motherboards seem to behave exactly as you've stated- almost NO difference.
True experience (new talk show, coming soon to an internet near you [TM]
I had an Asus A7M266 motherboard, which didn't have an onboard RAID controller. The A7M266 is one of those boards that has the hybrid AMD / Via chipset. I bought it for a new system (er, beginning of 2001), and wanted a RAID0 array for the new rig, among other things, so I also bought a Promise FastTrak100 PCI IDE RAID controller and 2x IBM 7200 RPM DMA100 60GB hard drives (never mind that they were listed as Maxtors, at the time I got them, I was actually happy that they turned out to be IBMs, since that was just prior to many people seeing them die, when their performance was the big ticket.)
The fact that the A7M266 has the AMD761 onboard allowed me to see the true performance capabilities of my RAID0 array. Since I initially set up the system for testing using a non-RAID configuration, and then went back and wiped the drives once the RAID card arrived, I got the chance to compare performance before and after. With the A7M motherboard and the Promise controller, the drives were close to 2x in performance much of the time (never actually doubled, but close), and always faster than a single drive setup.
Skip to the beginning of 2002. Snake's upgrade consists of an MSI KT3Ultra-ARU (onboard RAID133 Lite controller). Same hard drives. Okee. I try the drives in the non-RAID setup first (I always rebuild the complete OS on a major upgrade like this). Then I use the onboard RAID controller in a RAID0 setup. Huh? No way. The drives vary from a bit faster to a bit slower than the non-RAID setup. Well, maybe it's the onboard controller. So I disable the onboard, install the old faithful FastTrak100, and test again. Uh, this IS NOT right! Performance IS better than the onboard controller, but not by a whole lot. It's still not nearly at the levels it was with the A7M setup. Ugh.
So I did some looking around. There are a few (read: VERY few) that claim to have their RAID0 Via-based setups running well. The vast majority all report the same thing- PCI latency issues kill the RAID controller's performance with Via chipsets. This is an issue that has been ongoing through several chipsets now (including my KT333CE
If it weren't for the other benefits of this motherboard (Other than the PCI issues with RAID0, everything else works great, AND the support for PC2700 DDR is a Great feature!), I'd probably have returned it at the point that the PCI / RAID issue became apparent. I instead decided to live with it for now. But my next upgrade will most likely see me moving to nForce2.