I have a motherboard with a 2 (two) internal USB headers on it and I thought that each of those was a single port.
But I just went to the computer store to buy a card to adapt one USB header into 2 USB headers as below:
The guy in the store said that the 9 pin plug i connect to this header is actually half empty. i.e. USB is actually a four pin connection and although the cable has 9 female sockets, only four are used.
So in the picture above the bottom row is just plastic. It conducts nothing and therefore just covers a whole USB port according to the USB diagram below:
So whilst I only have 2 headers, I actually have 4 ports... tho 2 of them (bottom rows) are being wasted as they are covered by the 9 pin socket.
The store didn't have a card like the NZXT one above but the tech said I could just alter/shave the 9 pin socket I was connecting into the existing header.
He said the missing pin, pin 9 is for keying. This i understand in principle but not the logic. And he said the pin above that (pin 10) was for grounding and it could be ignored if I did want to plug in a couple of devices to each of the two rows of fours pins left over.
This I wanted to check.
So he's saying I can shave the 9 pin socket to use this:
into a 4 pin socket or join tow 9 pin sockets together to use the single header, like this:
Which gives me access to the bottom row / second port of the header.
This is fine for the top row, but for the bottom row , it seems to me if the extra grounding / NC is there (Pin 10) it's there for a reason. If it were just about keying, why wouldn't they have created a slot based mechanism for doing this especially since motherboard space is constrained?
I don't want to short anything out because I'm not using that grounding pin / NC pin. (Pin 10)
So is he right? Can I just modify the connectors and simply insert. I see Pin 8 is ground on the USB diagram anyway but if this is possible then why have I been supplied 9 pin connectors for my devices? Why do they deliberately "cover" pins they don't/cant use and waste a whole USB port?
Despite all the internet grumblings, the people that build these things are not stupid. They do what they do for a reason... but the tech guy at the comp store seemed pretty nonchalant about altering their connector.
Below is a picture of an adapter that came with the motherboard aligned as it would sit in the header and alongside that is a 9 pin female plug from the Cosair gears (they all look the same). As you can see, although the pin diagram I lifted off the internet says Pin 10 is NC, and the header adapter in this image says pin 10 is NC, the Cosair cable clearly has an extra thick black wire connecting to Pin 10 "for some reason".
What is that reason?
And why "block off" or "cover" pins 1,3,5,7 with a 9 pin female plug if they are not needed by the device?
My lack of understanding leads me to believe that once pin 10 is "used", pins 1,3,5,7 somehow become a risk to use hence the reason for blocking them off... but this just seems very wasteful. Why kill a whole USB port (1,3,5,7) ... just for keying... there must be a reason.