Asrock H81 BTC Pro Board and Sapphire Tri-X 290s

[Lynxh]

I got the USB powered risers from ^ to use with the H81 BTC, and like many of you, don't know what is the best method of powering the cards.

Two 860W PSU, six GPU (R9 270), one H81 BTC.

Do I want to connect power to both mobo molex and USB risers?
Or just use powered USB risers?
Or can the USB risers work without power connected, and power the two mobo molex?
If you strongly prefer a method, please give your reasoning.

I hope we can come to a conclusion, as there are many conflicting views.

[RickJamesBTC]

I got the USB powered risers from ^ to use with the H81 BTC, and like many of you, don't know what is the best method of powering the cards.

Two 860W PSU, six GPU (R9 270), one H81 BTC.

Do I want to connect power to both mobo molex and USB risers?
Or just use powered USB risers?
Or can the USB risers work without power connected, and power the two mobo molex?
If you strongly prefer a method, please give your reasoning.

I hope we can come to a conclusion, as there are many conflicting views.

You HAVE to power the riser, or the card won't work. This isn't a ribbon cable where power is moved to the card via the ribbon. The USB risers won't function without power connected to them.

Power from multiple supplies does not cause shorts. That's not how DC electricity works. The problem with ribbon cables that fail is cheap materials, cheap / poor connections with high resistance, and hooking up 6 cards that draw 35-70 watts through the pci slot connections when the motherboard has no provision for that kind of current draw.

[razerrr]

I got the USB powered risers from ^ to use with the H81 BTC, and like many of you, don't know what is the best method of powering the cards.

Two 860W PSU, six GPU (R9 270), one H81 BTC.

Do I want to connect power to both mobo molex and USB risers?
Or just use powered USB risers?
Or can the USB risers work without power connected, and power the two mobo molex?
If you strongly prefer a method, please give your reasoning.

I hope we can come to a conclusion, as there are many conflicting views.

You HAVE to power the riser, or the card won't work. This isn't a ribbon cable where power is moved to the card via the ribbon. The USB risers won't function without power connected to them.

Power from multiple supplies does not cause shorts. That's not how DC electricity works. The problem with ribbon cables that fail is cheap materials, cheap / poor connections with high resistance, and hooking up 6 cards that draw 35-70 watts through the pci slot connections when the motherboard has no provision for that kind of current draw.

No I got my problem solved.
It wasn't the fault of the risers, it was the fault of the energiecabel, i had in my psu.
Nevertheless.
Now I have two R290X on two different cabels, one in the x16 slot and one via riser in the x1 slot.
These risers are with power connector, but I'm not using it, the card works without the more energie.
I also have no extra energy connected to the mainboard.
This method works since several hours ( we'll see if something happens in future) on two systems ( both have the same construction).

[coincowboy]

How is your testing going?  I've had more problems with this motherboard.  I'm running a single 7990 and have to use the onboard 16x slot.  Even a powered riser in the 1x slot is not enough to keep things stable.

Someone wrote an article about how underpowered the 1x slots are on this board, even with the dual 4 pin molex extra power.

[RickJamesBTC]

How is your testing going?  I've had more problems with this motherboard.  I'm running a single 7990 and have to use the onboard 16x slot.  Even a powered riser in the 1x slot is not enough to keep things stable.

Someone wrote an article about how underpowered the 1x slots are on this board, even with the dual 4 pin molex extra power.

That doesn't make any sense. Your problems are likely in setup and drivers. Plugging a molex into the motherboard from the power supply will provide any power that a gpu may need, especially plugged into the 16x slot. It's just not that much power involved on that side.

[coincowboy]

Thanks Rick for your response

Have a look at this article:
http://bitcoinblogger.com/asrock-releases-bitcoin-mining-motherboard-1-year-late/

I can tell you I have completely reinstalled the OS, so I know there are no driver conflicts.  I've received no responses from people using a 7990, which is why I've posted in multiple groups - hoping to perhaps catch someone who in fact has.  That is why I'm posting to multiple groups - I'm hoping someone, somewhere has ran in to this problem.

In case you didn't know about the 7990, it's a beast.  It draws over 600W under full load (well under the capacity of the AX1200i I'm using), but look at the draw on the rail per connection.

https://i.imgur.com/fDQcqPa.png

I've only seen this board tested successfully with 270 and 280X's.  Which it has no problem with.  Yes I've seen people talk about having used it with R9 290s, but for how long and to what level of success?  You say you have multiple set ups with this - please share what they are.  Your knowledge of a successful set up may benefit me, that is, if you care to share.  

I've replaced everything from the GPUs to the risers to the PSU and I am getting similar results.  I've even moved the circuit from a standard 120V 15A to a 20A circuit.  The only thing that has not been replaced is the motherboard.

So please do share some suggestions.  I prefer to work constructively.  You say that's not how power works.  Please help me understand how it does.

I don't consider myself you average noob w/r to stress and load on systems.  I would love to be educated constructively.  So please do feel free to fill in some areas I may try.

[RickJamesBTC]

What am I supposed to be looking at ?  5 amps on the main 12v line, 7 on the peripheral? That's  60 and 84 watts. Nothing. The main power is the pci-e connectors at 17 and 26 amps. Like I said, they draw very little through the riser cards.
That article is about half wrong, and makes some stupid assumptions. Mostly that people are mining bitcoin directly with GPUs, but I don't need to be yet another person to call it bs.

I'm not talking driver conflicts, I'm talking driver versions. Things change, sometimes they don't work. I really don't have any help for you with windows, but I know the cards can work on risers without an issue, and the pro btc boards are cheap and effective. Toss BAMT 1.3 on a usb stick and try it.

[Damnsammit]

There is no reason not to use powered risers. If they have a provision for power, or if they are the USB style like I sell, they are designed to be powered. Not connecting them means that the power section was just on top of the existing connections. The USB style risers have no provision for power from the motherboard to the card, so they absolutely have to be plugged in.

Definitely agree with that!

However Asrock BTC boards have two extra 4pin connectors for the motherboard so the cheapest solution would be x1 to x1 unpowered risers. 

No harm in using powered in any circumstance ever though.

[bigblind]

i also ordered today
2x h81 pro btc
6x MSI r9 280X 3G Gaming
2x EVGA 1300 Supernova Gold PSU

How many cards do you think can i put PER mainboard with 1 EVGA PSU?
i also ordered 4 unpowered Riser as im going to use the x16 normally at first.

[molexman]

How should molex power be used in conjunction with 6 R9 290x video cards on a ASROCK H81 Pro BTC motherboard?
System:
 CPU - INTEL G3220 LGA1150 RAM - 4x G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) PSU 2 x Corsair AX1200watt - 1200 watts each = 2400 watts OS- BAMT

Confused as to how molex power via the powered risers is implemented or not implemented in this system.
i.e. Do i daisy chain 2, 3,4? gpu's through a 4 pin peripheral cable that came with my Corsair AX1200 PSU's? or Do I ignore molex power all together and just use the riser cables without attaching the 4 pin connector and letting it hang there?  Or do I use the 4pin power from the Corsair 1200 to plug into the two molex ports on the mobo and plug or not plug in the molex connector on the cards?  Aren't the 6 and 8 pin power plugs from the PSU already supplying the power to the R9 290x enough power for the cards?

If I am not plugging in the molex connector on my riser cards do I need to return the riser cables and get ones without the molex connector?

In the past I have made a few 3 card GPU scrypt mining rigs that used unpowered risers and gave me no problems setting them up.
I see different approaches on here -  i.e. not plugging in molex, or plugging in the PSU to the molex on the board but not on the powered risers.
Any help would be much appreciated because I am at a stand still until this issue is resolved. Don't want to fry anything.  
Feel free to let me know if you need any more information than I have provided.

[bit_coin_genuis]

Hi,

I just got this ASROCK motherboard after 1 month of wait as it was on backorder was very excited as i had read good things about it, but it is failing me.

ASROCK H81 Pro BTC motherboard
4 X sapphire TRI-X
4X unpowered risers ( as the board supplies extra power to MOBO with the molex connectors)
windows 8.1
SSD HD 120GB
4X SAPPHIRES r9 290 tri-x
12GB of ram
intel core i7-4770 CPU


I am losing my mind with this MOBO !

It does not work as advertised !

I can only get 2 cards to work at best ! ... and sometimes even thats screws up

1st PSU#1 (800W) connect to all MOBO connectors including 2X molex and 1 X GPU Directly in 16X slot (no riser)

2nd GPU on 1050W PSU#2 (unpowered 1x to 16x riser in 1x slot closest to CPU) works sometimes but mostly not recognized or has exclamation mark

3rd GPU on PSU#2, when by miracle windows recognises the 2nd GPU and I can hash with both I try and add third (tried in all other available 1X slots with 1X to 16 X unpowered riser. It wont boot up or I get the windows system recovery crap.

Someone please help I have been at it for 3 days and I am losing my mind!!!

[lebaillou]

Hi all,

Well, let me report my experience with this motherbord.
Doin lot of tests with it for the last 10 days.

// excuse my bad english...

Setup :
- PSU  corsair 750gold
- 5 GPU nvidia GTX 750Ti (for information, each caped at 55/60w at full load)
- running Windows 8.1
- my first rig

- with non-powered pcirisers : 3 GTX750ti max
- Non-powered pcirisers + extra molex pluged on MB : 4 GTX750ti cards max

And that's all...

So, i decided to investigate, seems like power was the issue.
Bought some powered pcirisers, made some tests...

Conclusion for me with GTX750Ti cards (that only consume 60w each, wich is very low compared to AMD Rx2x0 cards) :
Plug every cards with powered pcirisers...

Note : good tech to diagnose things if you have some doubt on your setup : launch one miner per GPU BUT not at the same time :
- launch GPU1 and wait until it mines at full load
- launch GPU2 and wait until it mines at full load
- .... until 6th card
So you'll know if you have some power issues.
You should spare some efforts and money by buying powered risers from the beginning...

So : don't rely on the power that is suposed to come from MB's PCI slots.

[IncludeBeer]

I see this thread is mostly dead, but thought I'd share my experience.  I'm using the H81 pro btc mb with USB powered risers.  In order for the mb to recognize anything plugged into the 1x pci slots, I had to connect the molex power to the USB risers I was using.  Now connected, and Win 7 recognizes all 3 cards and I'm hashing away happily