Just in the process of adding a couple of new SATA drives to my system. On unpacking the new drives I was somewhat surprised to see in the jumper settings that an option to lower the speed from 3Gbps to 1.5Gbps was enabled. Now the manufacturer probably enabled it for a good reason … possibly some older SATA controllers have a nervous breakdown when the faster drives are connected up, but I do wonder how many people have fast drives connected to fast modern controllers but have overlooked the switch and are running their equipment at a slower speed than is necessary.
It would be a good idea for disk manufacturers that do something like this to include a bigger warning about it. A little piece of paper with a big headline (“This Drive Is Configured To Be Slow And Safe”) and an explanation would be consumer friendly thing to do.
If you have newer SATA drives it may be worth spending half an hour hunting down their model numbers and googling for the manuals to see if they can be jumpered to a lower speed, and then checking if that has been done. You may get quite a speed increase by changing the drives!