Windows 7 USB PCIe 3.0 USB Card

seekermeister

Honorable Member
#1
I'm thinking of getting a couple of these cards for the two computers I have that only have USB 2.0 capabilities, but in shopping around, one small question has arisen...some of the cards have an interior 4 pin molex connector, which apparently is for providing power to higher powered peripherals, like this one:

http://www.ebay.com/itm/4-Port-USB-...rnal_Port_Expansion_Cards&hash=item4d0228cad7

What is confusing is that since the card is designed for connecting exterior peripherals, and USB 3.o is supposed to have the ability to provide power through the same cable as is used for data, what could this interior connection be any good for, except as just an auxiliary supply source to be used inside the case only?
 


badrobot

Senior Member
#2
That will be the source of power for the card itself and for the power that the USB 3.0 ports will provide to any peripherals connected to it.. It's not gonna get power from the motherboard. Just like when you connect a hard drive to the motherboard via SATA cable, you would also need to supply power to it using SATA power cables coming from the power supply.
 


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seekermeister

Honorable Member
#3
Then it still doesn't make sense to me. I know that normally USB 3.0 ports transfers power through the same cable as the data is transfered by, but via separate wires within the cable. Since this card is PCIe, I would think the same thing would true, because even the molex connector on that card has to obtain power from the motherboard via it's PCIe connection.

Even if I am totally wrong about this, it is obvious that means of connecting would be useless for connecting an exterior peripheral, because the cable that some cards provide are only long enough to reach something inside the case. If an exterior device required power from the computer, instead of having it's own power adapter, it could be accomplished by using an separate back panel connector that acted as an intermediary device to relay internal power to an external cable going to an external peripheral device. Somehow that card's molex connection seems extraneous to me.

EDIT: Rereading what you said, I think that you are saying that cable and connector are to obtain power directly from the power supply, rather than the PCIe slot...yes?
 


badrobot

Senior Member
#4
T

EDIT: Rereading what you said, I think that you are saying that cable and connector are to obtain power directly from the power supply, rather than the PCIe slot...yes?
Yes, that's right. But I think I was partially wrong when I said it's not gonna get power from the motherboard, it still is gonna get power but that would not be enough power for other peripherals or it wouldn't charge, say, a phone if you rely solely on the power coming from the motherboard (via PCIe slot).
 


seekermeister

Honorable Member
#5
Okay, then I really wouldn't need the cable, unless I had a special exterior device that would need it? At the moment, all of the devices that I have run fine on either USB 2.0 alone, or via their own external power source. Some of those PCIe cards come with the cable and others not, and I'm just trying to decide if that is a factor in deciding which to buy?

EDIT: What still doesn't make sense to me is that the cable that some come with is a 1 to four splitter, which wouldn't be necessary just to connect to the power supply.
 


badrobot

Senior Member
#6
It's not necessary if you have a spare 4-pin molex connector (from power supply) that has the right length to connect the card. The connector that comes with the card is a convenient add-on if you already have a connector going to another hardware inside your PC that is close to where the card is. Just split that power connector and you can use your spare power supply connector for something else in the future.
 


seekermeister

Honorable Member
#7
I went ahead an ordered a couple of these, but I'm still not clear about everything, because one of the ads had a statement in red, that said that the cable was need to power up the card, but if that was true, then it wouldn't require a 4 to 1 splitter. I guess I shall just have to wait until they arrive, so I can read the manual. Then again, considering the quality of some manuals, that might not help either.
 


#8
Think of it like a GPU...the PCIe slot is related to the bus speed in which the data is moved/passed on and then it requires a separate power source to actually turn it on and actually operate. Each device (PCIe slot and GPU) has to has it's own power source...the PCIe slot gets it from the mobo directly and the external device plugged into that slot has to be powered. Depending on what the actual unit requires for power to operate, the mobo power source may be enough and if not then it need some external power.

Example; a PCI USB add-on card wouldn't need and external power source because the device power needs isn't that great, in volts and amps....where as s GPU requires a more beefy power connection to supply power to the GPU's onboard components.
 


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badrobot

Senior Member
#9
You will really need to power it up. And you only need one 4-pin molex power connector. Splitter is only necessary depending on the configuration inside your pc.

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