I appreciate that. However, I am a 14-year veteran computer technician and technology writer. I would like to have what I asked for rather than advice. I need to know how this is done, not whether I should do it.
Wow, certainly not the way to get help on here. *bows to your holiness* I doubt you'll get help now. For all we know you could be some inexperienced user who has heard something from someone and is trying to fiddle with settings on their PC that they do not understand. You surely could have worded your response a tad more politely rather than effectively saying "I don't care, just tell me what I want" to which my response would have been "I am not aware of these settings".
Also notice how I did answer your original question:
All parts will work at their optimal speed automatically.
And what I said still stands, Parts will automatically select the optimal speed other than in some very rate cases such as auto-negotiation issues with some ethernet devices. I have a gigabit network, my network interface is automatically set to 1gbps, I have a SATA III 6gbps SSD, my SATA ports run at 6gbps automatically. There is not going to be a way to change these speeds other than to a lower value than they are currently at.
The Gigabit is used just for the users who need the speed.
The rest have to use the plain Ethernet.
The power users have two NICs n each the workstation.
No bridge. Lessor users can not get into the Gigabit.
Err... Gigabit does not require two NICs, almost all modern computers are capable of Gigabit, even 10gbps is now within reach of the average consumer (although expensive). All my machines run at Gigabit over basic CAT5e cable connected into their onboard NICs.
