Question Using a 2 x 8-pin PCIe cable but only connecting 1 x 8-pin ?

[guisado]

Greetings

I have this PSU and an RTX 3080Ti already installed using one of these cables

Now I want to install a second RTX 3080Ti, I've seen around that it's recommended to use two 8pin cables instead of 1 cable like the above (that branches into 2). So my questions, if some one could please help, are:

1. do you confirm it's safer to use 2 cables? (mind the already installed GPU is connected only with 1)
2. assuming above answer is YES: can I use a cable like the above, but only connect one end to the GPU -and use a second 8pin cable?

Thanks in advance!!

 

[SkyNetRising]

I want to install a second RTX 3080Ti

Why? For crypto mining?

1. do you confirm it's safer to use 2 cables? (mind the already installed GPU is connected only with 1)

Yes. It's better to use 2 cables. Cables will heat up less.

2. can I use a cable like the above, but only connect one end to the GPU -and use a second 8pin cable?

One cable end goes into PSU. The other end goes into GPU.
What would be the purpose for connecting only GPU end?

 

[guisado]

Yes. It's better to use 2 cables. Cables will heat up less.

One cable end goes into PSU. The other end goes into GPU.
What would be the purpose for connecting only GPU end?

Thanks for answering:
Well, it´s just that I have that very same 2x8pin cable already of the image + the regular 8pin cable, so I would be using 2 cables likewise (i'm an image guy)

 

[bill001g]

Not sure your question. You can just pretend the extra plug with the red x does not exist. Think of it as a extra outlet on a power extension cord you do not use.

Key here is you can likely do it which every way you like best. On quality power supplies like the one you have the wires on the cables with 2 plugs are large enough to actually run the same power requirements as running 2 cables with thinner wires.

The problem comes when you have cheap power supply. These manufacture will build things to the very minimum requirements and sometimes even below the requirements. Since you know there is more total copper running 2 wires it safer to do that than trust that a cheap power supply maker used the proper larger wires making a cable with 2 connectors.

 

[guisado]

Not sure your question. You can just pretend the extra plug with the red x does not exist. Think of it as a extra outlet on a power extension cord you do not use.

Key here is you can likely do it which every way you like best. On quality power supplies like the one you have the wires on the cables with 2 plugs are large enough to actually run the same power requirements as running 2 cables with thinner wires.

The problem comes when you have cheap power supply. These manufacture will build things to the very minimum requirements and sometimes even below the requirements. Since you know there is more total copper running 2 wires it safer to do that than trust that a cheap power supply maker used the proper larger wires making a cable with 2 connectors.

Yes, I think I was asking something like: "Can I wear an umbrela even if it's not raining?"
Needed to be sure, though.

Thanks a lot for your help!

 

[AntonyLovric]

Need to also consider stuff on the board side. You're putting ALL the power through the one 8-pin PCIE connector (probably exceeding the power it's supposed to be able to handle. It might work but it also might have a shorter lifespan. (What if it starts to work loose as well? And we're not even talking about traces around the PCI-E connectors....)

Using two (2) PCI-E 8 pins will reduce the power the connector has to handle, be more safer / redundant, etc.

 

[guisado]

Need to also consider stuff on the board side. You're putting ALL the power through the one 8-pin PCIE connector (probably exceeding the power it's supposed to be able to handle. It might work but it also might have a shorter lifespan. (What if it starts to work loose as well? And we're not even talking about traces around the PCI-E connectors....)

In the text above you mean using only one (1) cable with 2 8pins ends -like the first cable shown on the top of the thread- right?

Using two (2) PCI-E 8 pins will reduce the power the connector has to handle, be more safer / redundant, etc.

And here you are talking about using two cables, right?

Thank you

 

[geofelt]

Using both 6+2 pin connectors on a single cable has the potential to send some 300w. over the single cable connecting to the psu.
That is the potential problem. Some such cables can't handle that 300w. safely.
That said, your RM1000 is a quality unit so you should be ok.

 

[AntonyLovric]

In the text above you mean using only one (1) cable with 2 8pins ends -like the first cable shown on the top of the thread- right?


And here you are talking about using two cables, right?

Thank you

Yes