I found this strange problem when i was wondering why defraggler was slow (turns out defraggler just cannot handle too many files when doing a full defrag, and therefore uses 100% cpu)
I used process monitor to find out and here is the info:
Date & Time: ###
Event Class: File System
Result: FAST IO DISALLOWED
However, after the "fail" there is always a success listed in process monitor so im not sure if there really is a problem. But obviously id like Fast io processing for performance
I believe it has something to do with IOCTL_SCSI_PASS_THROUGH_DIRECT but im not sure if its even possible to tinker with a setting related to that, if so it should be the SCSI controller i believe.
Its just the basic scsi initiator which came with vista.