The Correct Way of Powering Your Risers for your RX 470/480

[adaseb]

Unfortunately the PCIe Slot power is at least 5Amps or so for the 470/480. Some of the 6 pin 480 even use much more than 5 Amps. You can't power too many of them with the daisy chain Molex and especially the SATA connectors. Even the 8 pin 470s draw around 5 Amps from the slot.

If you have the space, best would be to install NO MORE THAN 1 of your 470/480 directly onto the motherboard.

I would avoid using any SATA connectors to power any of the 470/480 GPUs. They draw at least 60 watts and those SATA connectors are generally used for hard drives which draw about 5 watts on average.




I wouldn't use any more than 1 of the Molex connectors to power any 470/480. Usually a PSU has 2 sets of these (6 molex in total) so you can power 2 GPUS from each seperate chain.



The best method would be as follows. Usually most PSUs have 2x 6+2pin on each chain such as follows.



You would plug in one of those to your 470/480 #1 connection and the other would always be unused. Since the length wouldn't reach the next card. So you would buy a PCIe extension cable such as below



Plug in the unused PCIe #2 connector to this extension and splice the other end +12V and GND directly onto your Risers power.



This way you could run any number of high power 480s and overclock them to the max and you would never have any melt since the PCIe has plenty of power and is a higher gauge.

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[janos666]

Nice warning about those kind of SATA cables. I burned a cable like that when I connected two RX480 cards to a single one of those. But the cable quality wasn't really great to begin with. The wires looked thick enough but the connectors were really loose ("pressured razor blades" kind of fitting in a lazy fashion). Although, 1 card works just fine if the cable quality (including the connectors) is decent (and you don't try to win overclocking contests).

I thought about modifying the risers like that but I ran into a false problem. I though: "nahh, the cards might need the 5V lane, not just the 12V". But I was stupid because I could simply leave the 5V wire as is (on a SATA/molex) and only cut/redirect the 12V. Although, as I said, 1 card per decent SATA cable works just fine for me, so I will leave it be. (But I replaced that PSU with one which has better SATA connectors. The old PSU could be hanging on the balance with 1 card.)

[jstefanop]

That wont work...the risers use, and need the 5v input from the molex.

[Grim]

yep riser needs 5v as well ...


What about DUAL sata power to single molex?!

The sata cable uses usually the same AWG wire size as the molex cable. The bottleneck is the PLUG itself!!!

Solution 2 sata plugs to 1 molex plug.

[kilo17]

I stopped using the USB risers a couple of months ago and have switched to exclusively using the ones below.  I stole Scotts picture (sure he won't mind the free advertising, and I was the one that got him to stock them )- I love them and would not use anything else - I have a big box of fried and non working USB cables.

[Rabinovitch]

I stopped using the USB risers a couple of months ago and have switched to exclusively using the ones below.

Is there a hot-plug bridge implemented in such kind of risers?

[Ginooo]

It's too late to see the warning.

my SATA connectors has bomb!!

[Trasamania]

I stopped using the USB risers a couple of months ago and have switched to exclusively using the ones below.  I stole Scotts picture (sure he won't mind the free advertising, and I was the one that got him to stock them )- I love them and would not use anything else - I have a big box of fried and non working USB cables.

https://i.imgur.com/5rYn162.jpg

I think that is a good choice.

[molitar]

My friend is running a rig with 4 RX 480 8GB Devil after market cards with the USB 3.0 and he has no issues. This tells me it's the quality of the risers you purchased are junk!

[Ginooo]

My friend is running a rig with 4 RX 480 8GB Devil after market cards with the USB 3.0 and he has no issues. This tells me it's the quality of the risers you purchased are junk!

must be 8pin~  my rx480 ref is 6pin，  so。。。

[kilo17]

My friend is running a rig with 4 RX 480 8GB Devil after market cards with the USB 3.0 and he has no issues. This tells me it's the quality of the risers you purchased are junk!

I have over 250 GPU's running and have been mining a long time.  I will be happy to show you a BIG BOX of worthless USB risers.  Every brand, color, manufacturer.  Secondly, If your friend is running some 480's it is probably a new build - give it some time. 

[Lerrcey]

I am running a 6x480 setup. 5 of them are on powered USB risers. I have 2 on a molex branch. 1 + MB on another molex branch. Then 1x Sata branch, 1x Sata branch. However I am now looking into the powered ribbon risers as advised to get shot of the USBs.

The USB cables are 500mm which just reaches the furthest card. The powered ribbon risers that I am finding are listing their ribbons length at 200mm so I am worried that not all the ribbons will reach all the cards. The obvious solution is to move the cards, which will mean redesigning the mounting cage.

How have you overcome this problem? and what is the layout of your graphics cards to ensure all of them reach the motherboard on these 200mm risers?


*edit add*.

You say the y split 6 pins wont reach two cards: How much spacing have you got between the cards? As my y splits allow a separation gap of ~40mm which, albeit early days, seems sufficient.

Also AFAIK each molex draws 5v, and the branch is rated to 12v. So as long as you don't use more than 2 (why the hell they designed it with three?!) then you will be within the limits +wiggle room. So what is wrong with having more than 1 per molex branch?

[BTCBusinessConsult]

My friend is running a rig with 4 RX 480 8GB Devil after market cards with the USB 3.0 and he has no issues. This tells me it's the quality of the risers you purchased are junk!

I have over 250 GPU's running and have been mining a long time.  I will be happy to show you a BIG BOX of worthless USB risers.  Every brand, color, manufacturer.  Secondly, If your friend is running some 480's it is probably a new build - give it some time. 

Kilo17 can you please provide a link to Amazon/Newegg/Ebay for the powered risers that you use and stand behind? I have done alot of research and have found quite a few that seems to work, but my mining farm is virtual... Ie it just exsists in my head since my wife thinks "Saving for vacation next summer is more important than your stupid mining hobby"... 

[twofreckles]

I am really confused... Not sure I understand it so Ill ask if my setup is OK (I know for sure such setups are working for over half a year now without any problems), but you never know...

So I am using such risers:

https://www.overclockers.co.uk/media/image/thumbnail/CB107OK_88534_800x800.jpg

So I plug the GPU with 8-pin connector plus plug SATA power cable to this Riser.

Running 5 or 6 GPUs on a rig, mainboard is ASHROCK H81 BTC PRO (this mainboard has also 2 additional power slots - which are plugged in as well).

Is there something wrong with such connection?

[kilo17]

My friend is running a rig with 4 RX 480 8GB Devil after market cards with the USB 3.0 and he has no issues. This tells me it's the quality of the risers you purchased are junk!

I have over 250 GPU's running and have been mining a long time.  I will be happy to show you a BIG BOX of worthless USB risers.  Every brand, color, manufacturer.  Secondly, If your friend is running some 480's it is probably a new build - give it some time.  

Kilo17 can you please provide a link to Amazon/Newegg/Ebay for the powered risers that you use and stand behind? I have done alot of research and have found quite a few that seems to work, but my mining farm is virtual... Ie it just exsists in my head since my wife thinks "Saving for vacation next summer is more important than your stupid mining hobby"...  

I have bought some from eBay etc but they are made differently than the ones I pictured above and are of lesser quality.  Those specifically I get from Padrino here on the forum or from Scott at HolyBitcoin.com (and he was sourcing them from Padrino as well).  Scott is excellent on shipping out in 1 day.  If he shows no or little stock just shoot him a message because he usually has more than is on his site.

I think  the ribbon is 9.5" long - it is plenty long for a 6 GPU rig

[Truthchanter]

I bought some of the 6pin powered risers from holybtc, will try them soon

[Truthchanter]

I bought some of the 6pin powered risers from holybtc, will try them soon

Unfortunately they are not working for me with 480s. Using these, the gpus show up in device manager but 10 or so seconds after I open my miner (claymore), the program crashes, the drivers crash, or they start mining but with some gpus at 0mhs.

I've tried powering them with only 6pin, only molex, and both 6pin and molex (since they have both connectors). My other risers (old molex powered ribbon risers and new usb powered risers) do not have any of these problems

[djole]

Is it ok to connect powered risers directly with the molex? I have a 5 non ref RX 470, all with 8 pin connectors.

[Truthchanter]

Is it ok to connect powered risers directly with the molex? I have a 5 non ref RX 470, all with 8 pin connectors.

Yes that is the best way. Although you may not want to connect more than 2 gpus per molex chain. 3 may be okay but I am not certain

[Trasamania]

Is it ok to connect powered risers directly with the molex? I have a 5 non ref RX 470, all with 8 pin connectors.

Yes that is the best way. Although you may not want to connect more than 2 gpus per molex chain. 3 may be okay but I am not certain

For the non ref 470, if it has 8 pin PCIE connector, you can connect up to 3, otherwise, it is safe to just connect 2.