HP Compaq dc7700 convertible minitower: SATA error

[magellan]

If I plug a device into SATA ports 2 or 3 of this system without fully populating SATA ports 0 and 1, I get a SATA error (even though the HDD still seems accessible and passes all tests). Why is this an issue? Why does the motherboard care that any particular SATA port isn't populated?

 

[kyij]

Maybe ports 3/4 are on a different controller with less performance? So they want to try and get you to use 1/2 first.