Disk half slow

You’ve just installed a new SATA disk, but you find that you are only getting half of the expected throughput. What is a likely cause of this issue?

A) The disk has a hardware fault

B) The drive is jumpered to the 150 MB/sec speed option

C) The SATA disk is connected to a PATA controller

D) The Windows disk driver needs to be updated

E) It’s early. The disk performs much better after some coffee and a few emails.