IDE controllers in a virtual environment operate on a polling model. The CPU must constantly check the status of the drive, leading to high CPU utilization during disk I/O operations. SCSI controllers, conversely, utilize interrupt-driven I/O, which is significantly more efficient.
Vmscsi-1.2.0.4.flp is a virtual floppy disk image containing the VMware SCSI controller drivers Vmscsi-1.2.0.4.flp