Figured out everything I needed. Had to use ES-Tool via http://www.samsung.com/global/business/hdd/support/downloads/support_in_es.html to alter the speed. Funny how the other two software methods came back with an error. Burn the image to a disc or a floppy and boot from it. Choose 'Set Max UDMA mode' and alter the speed to 150 and everything worked. Hope this helps.
Hello, I have recently purchased a Samsung HM641JI mobile hard drive and have had an issue with the SATA speed. The device I have been trying to connect it to (Playstation 3) has problems with the 3.0gbps, so I have been trying to switch it to 1.5gbps. I have used the software method provided by Samsung to make it slower but this seems to have not worked. What can I do to reduce the speed?