Why 6 pin and 6+2 pin?

[D1craig]

I have just installed a new gpu. I asked for plenty of help in tech support lol. https://www.pcspecialist.co.uk/forums/showthread.php?35446-Installing-my-gtx-770-How-do-I-do-it

I am just curious why does a gpu need a 6 and a 6+2 pin connected at the same time? I got a wire with it that allows a 6+2 pin to be plugged into it and splits off into a 6 and 6+2 pin.

I was wandering. Surely if a 6+2 pin can emulate them both at same time why does the gpu need both to be plugged in?

 

[steaky360]

I'm not 100% sure, but I figure its because of the amount of power that can be drawn through the 6/8 pin connections. Its probably easier to take the 8-pin power connection and distribute the power within the graphics card than it is from a 6-pin.

But I'm only guessing.

 

[mishra]

I think it is there to distribute the load evenly. Modern graphics cards are absolute workhorse and can draw enormous amounts of power. If you think about a GTX Titan, it can draw up to 250W !!! Asking to draw so much power on a single cable would mostly likely melt cables inside or it would brake the PSU. I'm no expert in this but I have seen attempts to connect modern GPU through selection of molex splitters that simply melted PSU cable and/or PSU itself. I suspect they could fit much thicker cables on PSU's to stop this from happening, but it is probably safer and easier to do it the way it's done.

 

[vanthus]

The two connections are needed with high end Graphic cards to spread the load over two rails of the PSU,using only one connection would exceed the maximum load allowed over one rail.

 

[D1craig]

So it's a good job I figured out what the splitter was for after I had already completed the job