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My motherboard requires 2 molex be connected for 13 gpus.

I'm using a server grade psu in conjunction with 160w pico power. The pico power has 22 awg wire which has 1 molex attached already.

My first thought was to add another molex to the pico power. However, based on @philipma1957 past experience, the pico may not be able to handle the extra (second molex) power being drawn by the board. It could melt the pico!

The current thinking is to add a molex on one of the lines coming from the server psu. But, since the server psu is 12v only, I will leave out the 5v which is usually used with a 4 pin molex.

Will this be problematic?


Thanks to @philipma1957 for helping thus far.

You don't need to use the motherboard molex PCI-E supplemental power when using all powered risers. You do need to disable the power check in the Bios or you will get a warning message at Post.

Thanks! Where is the "power check" in the bios? What's is called?

Also, per the manual, and because it's 13 gpu's, it says these molex must be plugged in. I have to believe it's for a reason since this is a "mining" board, and ASrock is well aware of powered risers, no?

Are you using this board now?

Is the "power check" option in the bios something different? Where can I find it specifically?

I think it's in the advanced menu > Chipset configuration. Look for PCI-E power warning or something like that and set it to disabled.

the reason is if you dont use powerered risers than you can connect the onoard molex and still have enough power.
if you look at the manual you can read that these molex supply extra power to pci slots

That's correct. The supplemental power ports are there so you don't burn up the PCI-E slots or motherboard when using unpowered ribbon risers. Theoretically anyways. Many people had problems using unpowered risers with the ASRock H81 Pro BTC.

https://forum.ethereum.org/discussion/7367/using-an-asrock-h81-pro-btc-board-beware

I've used Asrock H81 boards without molex.

However, the manual for H110 makes it sound like total meltdown if you don't use molex. Thought, maybe, since it's 13 GPUs, it might be different.

Thanks for the info!

I think they have the warning because the riser kits ASRock sells provide +12V power through a cable connected to the PCI-E slots. In that case, you definitely need to use the PCI-E supplemental power connectors on the motherboard.

http://www.asrock.com/mb/spec/card.asp?Model=BTC+PRO+Kit

USB powered risers supply +12V power directly from the PSU and there is only a small +3.3V current coming from the PCI-E slot through the USB cable to the riser. That's why ASRock lets you disable the warning, though they should make more clear when you need to use the PCI-E supplemental power connectors.

Vann, thanks! This is good news, and it saves me the hassle of custom cable work!

nice riser kit, i like :)
and yeah, those would need the molex connected

The ASRock riser kit came out when ribbon risers were popular. I'm not sure the ASRock kit is better than using USB risers. The USB 6-pin risers have four capacitors for a stable current flow and a voltage regulator to prevent spikes, which the ASRock risers don't have. It's also questionable if providing power from the PCI-E slots for 13 cards through the motherboard is a good idea. The ASRock riser kit is expensive at $30 each too.

I'm using USB 3.0 PCI-E 1x to 16x Powered Extender Riser. Version 006C. And they are 6pin powered. Edit: I don't use the crappy sata converter.
https://i.imgur.com/V8FDXRl.png

What does that mean?

oh i see, i thought they were new for the 13 pci slot boards.. this old overpriced hardware is not very good indeed.
them usb raisers are very good.. not much problems with them if you take care of them

 VERY good call.

 The original ASRock "BTC mining" motherboard design predates widespread use of powered risers - the current R2.0 version does not, but seems to have stuck with the molex on the motherboard design for backwards compatability, then they carried it into their 13-slot version.

 ASUS does the same thing on their 19-slot B250 BTC Pro design - but the board works fine without the molex if you use all powered risers.

Thanks! I'll be hooking up the H110 soon.

I suggest you use molex connections.

I agree with powered risers you should not have to.

how did this work out for you? :)

The extra power connectors are there for a reason. Its pure laziness not to plug power into them.

Also, you do not need the 5v for those connectors. I run a PCI-E to 3 molex cable to power my H110s directly off of a server PSU along with a 160w PICO

for me its not working if i unplug the molex with 13 gpus connected all powered risers the board will not boot it stucks at postscreen before the extended power message...

Sorry for digging up this old thread but I am about to build my first 13 GPU system using this port and I get mixed messaged when googling and also I am not sure if I understand what people said here on this specific topic.


So if I use molex powered risers (each of the 13 usb risers will be powered separately via molex)

Do I need to also plug the additional power inputs on the motherboard as the manual suggests? or will I melt my motherboard.

I really cant afford to melt it (and potentially the GPUs as well) so please answer only if you had this board or similar boards and know that the way you suggest will indeed work.

I thank you in advance.

If you don't understand the previous replies how would you know good advice from bad?
If you don't understand and are that concerned then don't take any chances, go by the book
and connect everything.

But it's always better to understand before doing.

In this very topic :

Saying I dont need to as long as I check a setting in the bios

saying that I dont need to


Saying that I need to.


saying that I need to.
And now you saying that I need to (also a few more posts saying that I dont need to but I omitted them)

So please dont be cynical, I am not an idiot in fact I worked as a computer technician back in the day and my gut tells me that it is unnecessary but as I said here and on what I can find by googling there are mixed messages about what to do and I cant afford to damage my mobo and potentially my cards just by going with my gut feeling because this is a non standart application and there might be electrical reasons against or for it that I am not aware of.

hence I am asking for the advise of people that actually WORK with this board, how they connect it in order to work without issues not for ironic posts like yours thank you

My cynicism has a purpose. It tells me if someone is thinking rationally or emotionally.

I read the entire thread and found it quite clear. Some advice was better than others
but it was easy to determine a consistent credible theme.

You seem to be asking for a blessing before you take any risk. IMO anyone can claim
anything and it means nothing. Your decision shouldn't be based on random testimonials,
it should be based on your understanding.

If you're truly unsure then don't take the chance, connect all the motherboard power sockets.
That's the best objective advice I can give.

Some unsolicited advice, using so many Molex powered risers doesn't seem to make much sense,
you won't have enough cables. You should only use one riser per cable unless you know otherwise.
It's better to use an 8 pin PCIe power cable with a splitter to power 3 risers per cable.

Some advice do 1 card.
Attach the molex to the board.
Add a card at a time.
Much safer as cards cost big bucks.