IOMeter - nForce4 - Transaction rate
How does array performance scale on the nForce4?

Nicely, that is until you hit that pesky performance ceiling above 16 outstanding I/Os. It looks like we're missing three- and four-drive RAID 0 results in the web server graph, but they're there, hiding right under the three- and four-drive RAID 5 results. Take away the parity requirements of write operations, and the nForce4's RAID 5 arrays perform just like RAID 0 arrays in IOMeter.