Noob question. Please help! :)

imeagles

Honorable
Jun 4, 2012
4
0
10,510
So i'm going to buy an EVGA 680 FTW edition which requires a 6 + 8 pin connector. I've located my PSU cables and i'm a little confused about something. On the end of the cable that goes to the PSU is only a single 12 pin connector, but on the side that goes to the video card has two 6 + 2 pin connectors, totaling 16 pins. Since the 680 i'm getting requires a total of 14 pins (6 + 8), can i use 14 pins even though the connector to the PSU only has 12?

P.S. My power supply is the Corsair AX 850
Thanks in advance
 
Solution
The thing about PCI-E power connectors is nvidia came up with the standard, and its stupid.

The 6 pin power connectors are not required to have 3 12V+ lines, they are only required to have 2. but everyone puts 3 anyway. On top of that the 6 pin connector is physically capable of providing 150W. The 8 pin connector only adds 2 ground lines. the 3rd 12V+ line is required but its always there anyway, so it doesn't actually provide any more power just more ground lines. So they are probably routing 2 ground wires to one pin on the PSU for some of them. Ground is ground so its the same thing.

The connections make sense if you think of the as power planes, but not as actual wiring. and since pcie is not a public standard and they charge a...

imeagles

Honorable
Jun 4, 2012
4
0
10,510
My main concern was that only 12 pins were going into the PSU but i will be using 14 (6 + 8) for my graphics card. But why would they make 16 pins (2x (6 + 2) if the 12 pins for the PSU wouldn't be enough.. lol
 
G

Guest

Guest
because 6 pins deliver 75 watts and 8 pins deliver 150 watts.

the pci slot supplies 75 watts. a 150 watt card would need a 6 pin, a 225 watt card would need two 6 pins. a 300 watt card would need a 6 and 8 pin power connection.
 
The thing about PCI-E power connectors is nvidia came up with the standard, and its stupid.

The 6 pin power connectors are not required to have 3 12V+ lines, they are only required to have 2. but everyone puts 3 anyway. On top of that the 6 pin connector is physically capable of providing 150W. The 8 pin connector only adds 2 ground lines. the 3rd 12V+ line is required but its always there anyway, so it doesn't actually provide any more power just more ground lines. So they are probably routing 2 ground wires to one pin on the PSU for some of them. Ground is ground so its the same thing.

The connections make sense if you think of the as power planes, but not as actual wiring. and since pcie is not a public standard and they charge a lot to.look at it we may never know.

Anyway. all that to say, its fine lol
 
Solution
G

Guest

Guest


i am sorry to get picky on you BUT ground sharing is a HORRIBLE practice and any offenders ought to be castrated!

a ground ought to be able to handle what load is being supplied. in the 12 volt world it wont be a factor but it is still good form to not ground share. but deal if high end professional audio or be connecting 600+ amps for 0/0 cable and it becomes a performance and safety concern very quickly.
 


I am well aware. The fact is though it CAN handle the load its being supplied. We've got 3 12V and 5 ground. Its just nvidias nutty standard that came up with this, probably due to the ground planes in the PCB but still... and in a PC power supply ground IS ground.

You're of course correct. I am well aware of grounding issues but we aren't dealing with signal processing here.
 
G

Guest

Guest
sorry, i didn't mean to question your knowledge . . i still have knee jerk reactions after spending many a hot afternoons in the sun on a field in the middle of nowhere setting up for some county fare with some local wondering how many "green wires" he can attach to a two foot copper rod that in the ground . . . yes TWO FOOT!