Power Connections

,

Maybe this is a silly question… But some of my AMD cards have an 8-pin and a 6-pin power connector.
I read that I should be using both of them. The card seemed to be OK with just the 8-pin.

Should all the power connectors be used or not? I think some of my Nvidias may also have multiples… Same question.

Just seems like a lot of connectors will be used up :frowning:

Yes, a lot of connectors will be used up and power issues are frequently the cause of rig shutdowns, freezes, intermittent errors, etc.

Don’t skimp on power if you are serious about mining and preventing fires.

  • Some GPUs will draw more power than spec from the PCI slots which adds even more risk.
  • Do not use SATA to 6pin adapters to power your risers
  • Do not use splitters on your VGA/PCI cables/PSU ports that did not come from the PSU manufacturer
  • Fill your GPUs VGA/PCI inputs in accordance with manufacturer guidelines
1 Like

I just received a new batch of risers that came with SATA adapter cables for power.

Are you saying not to use them?

I would not, ever. SATA connector spec stops at 54W and the PCI spec states 75W. A quick search with your tool of choice will provide plenty of melted connector and fire examples.

1 Like

Ok, duly noted.

Is it OK to power the riser with a molex connector (the old HDD power)?

Also, why do risers not come with any instruction on what to connect to what lol!

I mean we aren’t all born with innate knowledge :wink:

The order is:

  • 6 pin power cable (in modern times these are nearly always (6+2)
  • (in my opinion) molex with cables provided by the PSU manufacturer and stick to <2 per run, (1) for high powered GPUs that pull 150W+.
  • SATA to 6 pin = never/bad/don’t do it

Research a bit on the connector specs, there in are limits and safer expectations.

fwiw: the common 6/8 pin to 2x (6+2) splitters are cause for concern and create a large number of the troubleshooting exercises we go through daily. Yes, power supplies are expensive, but you are better off running more than (1) with proper cabling than risking a fire or significant downtime.

2 Likes

Ok, on GPURISERS.COM I found this in the FAQ…

How do you properly power a GPU Riser?
Our risers feature two 6-Pin connectors and one Molex connection. Only one of these connections is required to fully power the GPU Riser safely.

How many watts does a GPU Riser consume?
Our GPURisers.com branded risers consume 4~5 watts when GPUs are properly powered.

When is a GPU properly powered?
A GPU is properly powered when the usage in watts is less than the power being delivered to the card via onboard 6-pin and 8-pin connections.

What are the power ratings for 6-pin and 8-pin connections?
6-pin connections are rated for 75 watts, and 8-pin connections are rated for 150 watts

This tells me that as long as I am using both connectors on the card then I should be safe powering the riser with the molex…

They also warn about the SATA adapters

Do NOT power your risers with more than (1) power connector.

(1) 6pin

or

(1) Molex

My prior molex comment relates to the actual power supply cables, some have (4) Molex connectors on a chain, do not use more than (2) and with some GPUs, only (1).

GPURisers power consumption is the riser itself without GPU.

The GPU you put in it has been measured to pull more than 75W in some cases.

For instance, in this case… starting a new rig. Only have one GPU at the moment. AMD 580.

I am using the 8-pin and the 6-pin plugs to power the card.

I am now using a single molex to power the riser.

Gpurisers.com states the card would only try to pull power from the riser if it is underpowered, which shouldn’t be the case now that I am fully powering the card. 75 + 150 = 250 watts available to card.

Its a learning experience for sure. I see how important planning in advance is.

Thanks

Max power for an RX 580 I have seen listed is 185W.

Safest technically is one (6+2) power cable to the GPU and one 6 pin to the riser off another PCI/VGA port of the power supply.

The alternative is one (6+2) power cable to the GPU and one molex power cable to the riser.

Your 580 is old enough to have a legacy 6pin for early 201x power supplies. That design implies 75W from PCIe slot and 75W from the 6pin.

This topic was automatically closed 416 days after the last reply. New replies are no longer allowed.