Disk Throughput test

[Stephen Sanders]

FreeBSD 6.3
Dual Quad Core Xeon 5450 at 3Ghz
16GB RAM
3Ware 9650SE-ML / 256MB cache
14 Seagate 750GB/7200RPM/ST375033ONS SATA drives

We have an application that is streaming data to disk at the maximum
rate the controller can sustain.  The controller should be able to
develop something on the order of 600MB/s but we're only getting 450MB/s.

The application writes about 50GB into a file, closes the file, and then
starts another file.

I've set all of the recommended settings from 3ware.  I have tried
various settings for vfs.hirunningspace - various settings include
everything from 5MB to the cache size of the card (256MB).

Does anyone know if there is some file system performance limit?

Thanks