[SOLVED] Does an 8 to 8 power connector give same power as an 8 to 8+6?

Solution
That cable is a 2x8 pin, essentially - and you can use both connectors on the GPU side daisy-chained, as I described.
There's two 'sets' on there, of 6+2. You use the full 6+2 to form an 8pin, and only the 6 pin element of the second.

Visual:
c76mfwu1jf4g.png


The "red" (in this image, yours won't be) connects to the PSU - #1 & #2 are connectors for the GPU - you can use both.

The GPU likely won't post with only an 8 pin connected and, if it does, it's not receiving full power.
As SkyNet mentioned, the pin "out" on the PSU side of things can provide enough 'power' for an 8+8 configuration down a single modular cable with a daisy-chain setup.

Barty1884

Retired Moderator
"Power"? No, at least, not in theory.

By spec, each connector has an upper limit of power it can draw.
A 6pin is spec'd for 75W, an 8pin is 150W.

So, an 8+6 has the physical power setup to draw ~300W (6pin + 8pin + PCIe slot) whereas an 8+8 could theoretically draw 375W.

Just because the cable is spec'd for it doesn't mean the GPU will be drawing it though.
 
Feb 20, 2019
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615
"Power"? No, at least, not in theory.

By spec, each connector has an upper limit of power it can draw.
A 6pin is spec'd for 75W, an 8pin is 150W.

So, an 8+6 has the physical power setup to draw ~300W (6pin + 8pin + PCIe slot) whereas an 8+8 could theoretically draw 375W.

Just because the cable is spec'd for it doesn't mean the GPU will be drawing it though.

Yeah, i was just wondering that if the 8 to 8+6 pin will deliver more than an 8 to 8, even if both of the power supply ends are 8 pins.

So can the powersupply deliver more to the 8+6 cable, even if it is connected at its end only in 8 pin?
 

Barty1884

Retired Moderator
I don't know what you mean? If only an 8pin is required/connected, that's the theoretical max.

It's mostly a moot point anyway, the performance difference between most 8+6pin powers GPUs vs the same GPU with 8+8 are going to performance with a couple % of one another.
 
Feb 20, 2019
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6
615
I don't know what you mean? If only an 8pin is required/connected, that's the theoretical max.

It's mostly a moot point anyway, the performance difference between most 8+6pin powers GPUs vs the same GPU with 8+8 are going to performance with a couple % of one another.

Okay so i currently use a 8to 8+6 pin (psu to gpu). But visually id rather use the 8 to 8. Is there a power drop? Difference?
 
Feb 20, 2019
128
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What power supply are you using? Model name?
Best option would be using one 8 to 8pin cable and one 8 to 6pin cable (or 8 to 6pin +8pin and leave 8pin hanging).

I have the evga G3 550/650 w

I only have two cables to choose from 8 to 8 and 8 to 8+6 (psu to gpu)
Do i get the same power from them? because id rather use the 8 to 8 for visual reasons

And my gpu (1070ti) has 8+6 pins
 

Barty1884

Retired Moderator
There is no 8+6 cable?

There is also no G3 550/650W. You have one of those?

Either way, the G3 550W has 3x 6+2 pin connectors.
One of those cables has two separate 6+2 connections on it.
You connect the 6+2 portion = 8pin, and only use the 6pin of the second 6+2 (either on the same cable, or from another dedicated cable from the PSU), to populate your 6pin on the GPU.
 

Karadjgne

Titan
Ambassador
2 different types of pins. They don't line up with standard thinking.

The pins on the 6+2 gpu end of the cable are rated at 5A per pin, the pins at the psu side are rated at 9-11A per pin. The output of all 4 pins on psu side is @ 430w-510w, vrs the 360w capable by a 6+2 / 6+2 gpu.

So the actual number of pins doesn't line up 1-1. It's a modular connection is all, to take the place of a hardwired solder connection inside the psu.

The cable used won't matter, if you want to use the 6+2/6+2 that's fine, but you'll only use the 6+2/6 as a hookup, the extra +2 off to the side as the gpu won't fit it. If you want to use the 6+2/6 cable instead, that's also fine but there will be no dangling +2. You just won't connect the other cable, whichever you choose, because it's unnecessary.
 
Feb 20, 2019
128
6
615
Use both of those cables. One cable to connect to 8pin, other to connect to 6pin connector.

If you're considering to use single 8pin to 8pin cable, then this will either put your graphics card in low power mode or melt cables. Don't do that.

I only have a 8 to 8+6+2 cable, and 8 to 8 cable. So while the other cable could plug into every single gpu socket, it would only be 8pin when connected to the PSU. So i currenlty use (8from psu, to 8+6+2 in gpu, of which i use the 8+6 and leave the 2 pin hanging out. Could i rather use the 8 to8 pin on gpu (leaving the 6 pin on gpu empty)

Because if both of them are connected with 8 pins at the PSU side, wont they have the same power or what?
 

Barty1884

Retired Moderator
That cable is a 2x8 pin, essentially - and you can use both connectors on the GPU side daisy-chained, as I described.
There's two 'sets' on there, of 6+2. You use the full 6+2 to form an 8pin, and only the 6 pin element of the second.

Visual:
c76mfwu1jf4g.png


The "red" (in this image, yours won't be) connects to the PSU - #1 & #2 are connectors for the GPU - you can use both.

The GPU likely won't post with only an 8 pin connected and, if it does, it's not receiving full power.
As SkyNet mentioned, the pin "out" on the PSU side of things can provide enough 'power' for an 8+8 configuration down a single modular cable with a daisy-chain setup.
 
Solution

Karadjgne

Titan
Ambassador
The psu connector doesn't count. It's proprietary to that psu. It could be 4pins, 6pins, 8, 10 or 12pins. It's just a modular connection. The only thing that matters is the gpu end. You don't have an 8 to 6+2/6 cable, you have a 6+2/6 and a 6+2/6+2 pcie cable, both of which are interchangeable on the pcie modular connection ports which happen to use proprietary connectors. That happen to have 8 pins.