It seems I.T. likes to set up a single channel RAID 5 which in my opinion is the worst possible setup for sql server (50 MB/sec limit) with a severe 4x write penalty. My preference would be three i/o channels to RAID 1 (50 MB/sec x 3) and use filegroups to assign clustered indexes and non-clustered into two channels and one channel for the log.

Alternatively I just push for purchasing more RAM so the only disk channel is mostly used for log writes while the database stays in data cache.