The raid systems use the following sata disks:
Western Digital 2500SD with an 8MB cache, spinning at 7200rpm. These disks also have a transfer speed of 1.5Gb/s.
Our current linux systems tend to use the WD 2500JB EIDE disks, which have an 8MB cache and spin at 7200rpm, but only have a transfer speed on 100MB/s.
In the future, machines that connect to the gb network should have disks with the faster transfer speed put in them.