Mixing Sata 2 with sata 3 2011 Mini

I am going to assume that everything is working right and its just slowing down to the weakest/slowest link.

I have owned many of the G4 and C2D mini's in the past.
Found a rather nice deal on craigslist for a used in the box 2011 i5 mini for $200.
It came with the 500gb sata3 drive and the negotiated speed was sata3 600
I decided to ebay purchase a second drive cable kit and use a WD 640gb sata2 drive I pulled out of a previous mac I owned.

Now the negotiated speed reflects sata 2 speeds on both drives/channels

I am assuming that is correct and not a cable issue, its not like sata2 or sata3 matter with spinner mechanical drives as I will be lucky to see 200

Thank you, that is what I figured, Was first thinking i may have had a bad second drive cable.
I am surprised they have not separated each channel from master/slave over all these years later.