This integer reports the width of the target device's SCSI data bus as actually negotiated between the controller and device, expressed in bits. Comparing it against cpqScsiTargetPhysWidth tells an admin whether the device is running at its full supported bus width or has negotiated down. For example, a device with a 16-bit physWidth but a negWidth of only 8 would indicate the bus negotiated to a narrower width than the hardware supports, worth investigating.