Recoverability is the only consideration in deciding whether write cache should be disabled. If you have a RAID controller or if the disk controller has a battery back up, it does not matter whether write cache is on or off.
In the absence of either of the above, disable the small computer system interface (SCSI) controller write cache to avoid the possibility of losing data. At a programming level, if the SCSI write-through flag is set, Windows NT does not use buffers but writes directly to disk. When a program receives a write-complete signal from Windows NT, it has a guarantee that the write was completed to disk. This guarantee is critical to the Microsoft Exchange Server transaction logging process. If write cache is enabled, Windows NT cannot discriminate between whether the SCSI controller cached the data or wrote it to disk so it erroneously informs the calling application that a write has been made, which could result in data corruption if your computer crashes before this lazy-write operation makes it to the disk.