Topic: Motherboard designed for mining, and better riser cables in this thread. - page 3. (Read 63328 times)

Just use USB risers, like in my sig
The risers you are using don't have the presence pin shorted, so they don't register in the 16x slots.

I have a riser question.

I'm using a Asus P8P67 WS REVOLUTION motherboard which has 4 PCIx16 and 3 PCIx1 slots.

I have GPU's directly on the MB in the x16 slots, and I'm using risers to get additional GPU's into the x1 slots. This all works, but is a big mess. I'd like to use risers even from the x16 slots so I can build a separate case.


So I just tried the x16 to x1 risers (+molex) that I'm currently using from the x1 slots. HOWEVER, those risers don't work from the x16 slots - ONLY from the x1. The cards just vanish from the O/S.

Do I need to use x16 - x16 risers (or an otherwise special type of riser) to rise a card from a x16 slot?


Preferably I'd just like to USB 3 risers for all the cards, if possible?

Just because a motherboard has 6 slots does not mean that you can use them all at the same time.  There are also some motherboards that are finicky or require little tricks to make them work right with all of the slots occupied and the manufactures can provide almost no support or information on the topic.  I would guess that the majority of the community uses intel boards because at one point in time one person said "hey this board works great" and it happened to be an intel board, so then everyone bought that board rather than buying one and taking a gamble/swearing at it for days before you get it to function if you can get it to work at all.

Some of them don't like risers, some of them don't like usb risers but are ok with regular risers.  Some of them will only work if you use risers in certain slots. Some of them need presence pins jumped.  Lot of pain in the ass variables when you can just get a board that you know will work.

I have ran 6gpu amd boards and all but one I worked with was a pain in the ass.  and the good one is discontinued and cant be found anymore.

RANDOM QUESTION so why does the pro BTC board use intel? AMD cpu's so much cheaper. It also seems that most 5+ gpu boards people use are intel. Are the AMD ones like UD7 not as good?

Not necessarily. The retail price of that motherboard is 69 bucks, which is much cheaper than other 6 gpu capable boards. It's not required to plug in the molexes on the motherboard since they only supplement the existing 12v power from the ATX connector.

My card isn't being detected by the PC when on a USB powered riser. Any reason for this? Is there a setting which needs to be changed from BIOS?

If one was to buy USD risers, would it resolve shorting pins and powered/not powered issue?

I honestly don't know the current market, but I bought a whole bunch of z77a-gd45's for $75 bucks ea. over black Friday. You can still find them occasionally, for $75-100. The GD65 is another good one, though a bit more expensive.

What's your recommendation on Best Buy Mining board out there ?

hah, the exact same reason why I ain't buying it, the resale value will decrease a lot.

And it would actually be worth something when you went to sell it in a few months/years.

That board is a gimmick for noobs, as pointed out previously.

Well... If I go with powered risers whats the point of buying H81 Btc Pro if it's not for using its molex connectors on board. I can just buy cheaper one and go with powered molexes... It would be the same thing.

Lots of good info in this thread, I also want to thank llamabucket and pontiacg5 for their insightful conversation, as I too am in the process of building a rig, using 6x GPU (R9 270), the H81 BTC, and two 860W PSUs.

I've read everything, but still would like to ask again for clarification, due to what  nvandertill said about it being okay to run powered risers and still plug into the ASRock mobo's molex.

What you said about 75W being spread over 5-6 PCI-E lanes being insignificant makes sense to me. Since there is a lot of mis-information about these boards frying, once again:

1. Why are some people frying their H81 BTC boards by using powered risers + mobo molex supplement? Is it because they are powering the GPU with two different PSU rails?

2. I guess since llamabucket got his board running with 5x GPU with powered risers, minus the molex power supplement, what possible harm could there be from adding power to the mobo molex?

3. Total newbie question: if I got two identical 860W PSU, how do I avoid "mixing rails" and connecting 6x R9 270, mobo, cpu, etc? Please spell it out for me, including which connections to which, etc
I have powered USB 3.0 risers in the mail, and will be using these for all 6 cards, just looking to get some confirmation.

I am very cautious and want to do this right, thank you for reading!

It is best to have 12V power directly at the GPU, not stuffed through a ribbon cable. As you push the limits on this stuff the current required will increase exponentially, and the power supply will comply till it can't any more, there is no regulation on the motherboard, or the molex cables running to the board. That is what burns stuff up. For the cost, why would you not use a powered riser? Not like they are the best made pieces of work ever made...

But you do what you do, save three dollars. After three pages if you still can't get the idea that powered risers should always be used you deserve to burn stuff up.  

I plan on using 3 cards max on the H81 Btc PRO so that's why I'm asking would it be enough only to have molex connectors connected on the board without powered risers? I can easily purchase those but I am just wondering.

Thanks for the reply. I'm sorry but I only worked on notebooks before... I never even had a PC in the house before, the learning curve wasn't the same for me. Some people say notebooks are more difficult to work upon than PCs, but it sure isn't looking that way to me so far. I shouldn't even be apologising though, everyone has to start somewhere at some point and I really appreciate all the help you can give me.

P.S. - nice setup you've got there!

You hook the sata connections up to the power supply. If that is not obvious you have no business mining...

Yes, the riser cables are safe to use. Here is a wall of 24 GPUs and USB risers, running on 8 power supplies. Scroll through my photobucket if you'd like more, I think there are pictures of 3 or more PSUs running one rig.



The guy in that thread you linked to has no idea what he is doing, apparently.

Also, try not plugging the USB riser cables in (power) and see how far it gets you.

I bought 4x USB risers, and I have a couple of questions to ask (they're a bit noobish so bear with me please). First of all, where do you have to connect the black SATA connector?



Secondly, do you need some other cable? That molex-to-SATA cable looks too short to go anywhere.

Thirdly, I just read this topic:

https://bitcointalksearch.org/topic/blew-up-2-mining-rigs-with-riser-cables-437599

Are these USB risers safe to use?

Edit: my mobo is an ASRock 970 Extreme 4, if that helps. Do I really need to power the risers for them to work?

As I did, a year or so ago, with a gigabyte G1.sniper3. It still mines to this day with 4 7970's.

I give up, not like anyone reads what you say anyway.

I'm not using this specific board, but I am using a board that provides extra molex connector which supplements the PCI-E lanes. It is also ASRock brand, but higher quality. I am running 5x R9 280x per board. I use all powered risers and the extra molex on the board. Did your comment apply only to the specific board that was on topic or all with PCI-E supplement molex? I've been successfully running 2x rigs (clones) this same way for almost 3 months now with no issues...

From what I understand, molex connectors generally provide around 75w of power per connector. 75w spread over 5-7 PCI-E lanes is not much for a power hungry GPU. Now 75w extra per card (via riser) is a good solution to get the card the power it needs. I don't think it would fry it. It's not going to pull anymore power than the GPU is asking it for. Generally PCI-E lanes are burnt out when you don't use powered risers because the card is trying to pull more power through the bus then the bus is designed to handle. This is why you supplement on the riser itself. Just because the power is available doesn't mean the GPU is using it. This is given the exception of a power surge, in which case the power is forcefully pushed into the circuit and therefore the hardware that is not designed to handle so much current which ends up frying it.

I suppose it all depends on how many GPUs you intend on running off the board what you would need to do. Personally I would always use powered risers for all GPUs.