Question Some explain PCIE power to me please?

[johnrob]

I need help understanding pcie power connectors.

Up until now in my life I have never dealt with a 6 pin pcie connector. It's been 8 or 16 in my experience.

Now I have a GPU with 1x 8 pin (6+2) and 1x 6 pin port

From my understanding, the 8 pin port can draw 150w and the 6 pin can draw 75w, add in the 75w over the card slot and I'm at 300w.

It's also my understanding that a 6 pin Peripheral/SATA connection is okay for 75w.

So if that's the case it makes sense to use 1 pcie port on my modular PSU and 1 SATA/peripheral port.

It would also make sense to me to use 2 pcie ports and just cut the jumped "+2" connection out of 1 of the cables.

Aesthetically, a hanging +2 connector is not acceptable to me.

Can anyone explain this?

 

[shknawe]

What is your psu, gpu and what are your system specs?

 

[Rogue Leader]

I need help understanding pcie power connectors.

Up until now in my life I have never dealt with a 6 pin pcie connector. It's been 8 or 16 in my experience.

Now I have a GPU with 1x 8 pin (6+2) and 1x 6 pin port

From my understanding, the 8 pin port can draw 150w and the 6 pin can draw 75w, add in the 75w over the card slot and I'm at 300w.

It's also my understanding that a 6 pin Peripheral/SATA connection is okay for 75w.

So if that's the case it makes sense to use 1 pcie port on my modular PSU and 1 SATA/peripheral port.

It would also make sense to me to use 2 pcie ports and just cut the jumped "+2" connection out of 1 of the cables.

Aesthetically, a hanging +2 connector is not acceptable to me.

Can anyone explain this?

I don't know where you got the idea that a SATA connector is good to 75w, its not. In fact a whole SATA cable to the PSU is rated only to 54 w with the assumption that nothing connected to it would pull 54w in and of itself, but if you were to populate all the connectors on it it has 54w in theory to play with.

Aside from the fact using adapters is ALWAYS a bad idea.

If you must you could in theory cut the +2 connector off your 6+2 PCIe cable, and just make sure you tape up the ends to be safe. Thats the only way to do what you want to do aesthetically safely.

 

[geofelt]

What is the make/model of your psu?
Quality counts.

All the PSU's I know of that have two aux pcie power leads will either be low power units with two 6 pin leads or they will have multiple 6+2 leads.
You will just have to tolerate the ugliness of a hanging +2 part.
Of course, you could simply cut off the dangling +2 part if you wish to satisfy your aesthetics.

 

[jankerson]

What is the make/model of your psu?
Quality counts.

All the PSU's I know of that have two aux pcie power leads will either be low power units with two 6 pin leads or they will have multiple 6+2 leads.
You will just have to tolerate the ugliness of a hanging +2 part.
Of course, you could simply cut off the dangling +2 part if you wish to satisfy your aesthetics.

Or just zip tie it down...

 

[johnrob]

This power supply: https://m.newegg.com/products/17-139-246

It's 750w and has 4x 8 pin ports (CPU and PCIE)

Is it possible to run a 6 pin to 6 pin cable from the PSU to the GPU? Or does it need to be 8 pin to 6 pin?

 

[Rogue Leader]

This power supply: https://m.newegg.com/products/17-139-246

It's 750w and has 4x 8 pin ports (CPU and PCIE)

Is it possible to run a 6 pin to 6 pin cable from the PSU to the GPU? Or does it need to be 8 pin to 6 pin?

Thats a good quality PSU.

Yes that is possible but you would need to find someone who actually makes such a cable specifically for that PSU. There is no "universal 6 pin" and if you were to take one from another PSU and do it theres a good chance it will fry both the PSU and GPU.

Cablemod offers products like this

CableMod – Cables Perfected.

cablemod.com

 

[scout_03]

if you have all the cable that come with psu you only need to use 2 of them to power the gpu plug in the psu gpu output no need to have cable cut or others since those gpu cable are double connector and could handle 2 gpu .

 

[johnrob]

So It's my intention to just modify the cables that come with the PSU, I have ATX pins, crimps, a pin extractor, etc.

hopefully the PSU will include a manual that has a helpful pin out or something, but it's my understanding that the GPU connector for 8 pin is 4 ground over 1 ground and 3 +12v, and for 6 pin it's 3 ground over 3 +12v

Another questions related to this: why can the 6 pin only provide 75w if both 6 and 8 pin have 3 +12v conductors? (8 pin provides 150w)

 

[Rogue Leader]

So It's my intention to just modify the cables that come with the PSU, I have ATX pins, crimps, a pin extractor, etc.

hopefully the PSU will include a manual that has a helpful pin out or something, but it's my understanding that the GPU connector for 8 pin is 4 ground over 1 ground and 3 +12v, and for 6 pin it's 3 ground over 3 +12v

Another questions related to this: why can the 6 pin only provide 75w if both 6 and 8 pin have 3 +12v conductors? (8 pin provides 150w)

Its really just the additional grounding of the 8 PIN that is part of the specification. Its not that it physically can't do it, in theory it could, but the PCIe spec says 6 pin 75w, 8 pin 150w and that 150w is provided due to additional grounding.

There really isn't much modification to do at all, just remove the additional +2 pin from 1 cable and trace it back to the connector and remove. Me personally I'd do it with a spare cable, or just buy the Cablemod ones, just in case you end up needing the cable to be correct in the future.

The PSU does not have the Pinout info in the manual, they don't expect people to do this, you're flying blind on this one, so I would suggest don't make guesses, as you WILL regret it.

 

[johnrob]

Yeah I think I'll make a pinout for the pcie cables once they get here and copy them essentially. Smart to not mess up the originals

 

[Rogue Leader]

Yeah I think I'll make a pinout for the pcie cables once they get here and copy them essentially. Smart to not mess up the originals

You could also probably buy a spare to modify from Corsair, they can't cost much.

 

[hang-the-9]

I need help understanding pcie power connectors.

Up until now in my life I have never dealt with a 6 pin pcie connector. It's been 8 or 16 in my experience.

Now I have a GPU with 1x 8 pin (6+2) and 1x 6 pin port

From my understanding, the 8 pin port can draw 150w and the 6 pin can draw 75w, add in the 75w over the card slot and I'm at 300w.

It's also my understanding that a 6 pin Peripheral/SATA connection is okay for 75w.

So if that's the case it makes sense to use 1 pcie port on my modular PSU and 1 SATA/peripheral port.

It would also make sense to me to use 2 pcie ports and just cut the jumped "+2" connection out of 1 of the cables.

Aesthetically, a hanging +2 connector is not acceptable to me.

Can anyone explain this?

I always say, a good way to break something is to try to "fix" something not broken. I would not try to make a custom cable just to hide two un-used pins that can be easily adjusted so you can't see them unless you are staring at your computer insides looking for them all the time. Shorting out a power supply and video card does not seem like a good risk in return.