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I keep seeing mixed answers to this question. One blog says using unpowered risers still won't work even though the mobo has 2 4 pin molex connectors, however, others have said you shouldnt use any powered at all?

Is it safe to say if I want to run 6 7950 GPUs maybe I should use 3 powered and 3 unpowered?

Thanks

Powered risers are so that you don't pull too much power through your MB. If each GPU pulls 25W, a 6 GPU rig means you'll pulling 150W through a board that's not designed to have that much power running through it. Things get hot, and they fry.

The Pro BTC MB has 2 separate molex connectors for supplying extra 12V power to the MB, specifically to the PCIe lanes. It's designed so you won't have to use powered risers.

I mean, you still could if you wanted to, but it'd be kinda pointless.

Yes always use powered risers so shit don't melt

I wouldn't bother. I have a G3 sniper quad 7970 setup with extra power for the mobo and have been running that rig 24/7 for 9 months without a single problem. Im using x16 unpowered risers on all of them.

Okay so I am running 6 7950's right now and I have a 1000w and 700w psu running. I plugged in all 6 cards and and I have the 4 pin molex going into the 2 slots in the board, it turns out only 4 or 5 card will run out of the 6 for some reason.

I ended up having to use 4 powered risers and leave 2 unpowered for all 6 to work, I might be able to get away with 3 powered and 3 unpowered but w/e. It looks like you still need powered for this board...

Wait, so you're saying the motherboard with the word "BTC" in it turned out to be a gimmick of sorts? No way!

Jokes aside, I was really hoping unpowered risers would work fine with this board as I am going to order parts this week and would love a motherboard that works great out of the box with more than 4 GPU but I am having a lot of trouble finding something like that.

It works great out of the box with the right driver it recognizes 6 GPUs, and I think if you plug the 2 molex into the board you can run 4 GPUs unpowered, but after that you might need powered..

@Ratman2050: wich Driver Version are you using to run 6 Cards?

13.1 driver. The driver is from this thread: https://bitcointalk.org/index.php?topic=193695.msg2526454#msg2526454

Here is the link: https://www.dropbox.com/s/1hoxkz0y8fe933g/13-1_vista_win7_win8_64_dd_ccc_whql%20Working.exe

Thanks! Have you encountered any issues when using powered risers with your h61 pro btc? Cause I have. https://bitcointalk.org/index.php?topic=454205.0

I did not attach the molex plugs onto the mobo, only onto the powered risers.

Yeah one of my mobos failed because I had a voltage issue. Idk what the real problem is maybe something to do with the rails and powered risers but I thnk from now on I am only gonna power 3 cards out of 6, and the 3 cards I power will be the ones I connect to the mobo.

I really like the H81, i just wish i was able to get all non/powered.  After multiple testing I was able to get 5 cards running good with non-powered risers.  One card no matter what with non-powered one seems to run around 80khs (all cards are 280x's) so that is horrible.   As soon as parts get here Monday splitting between two motherboards.  Using two corsair RM 1000's as PSU's.  

Windows 8.1, all latest drivers.

Is it better with powered riser?

Hoping to find that out soon when some hardware hopefully arrives (hopefully today).  All  my powered risers were in use and didn't want to take apart working rigs.  My review so far is good motherboard, but a little over hyped from them.  Looking back I should have just used all usb riser's and gotten the extra distance on risers.

Stupid question...

Can I powered risers without plugging them into power? Will they operate just as unpowered risers would?

No make sure to plug them in.  I wish we could as i would just use USB risers for everything. 

A update was able to get ALL working.  One card still runs slower then others 600ish isntead of 700ish.  But much better then the 80 i was getting.  Turned out i disabled and then enabled devices one by one it worked.  So far 5+ hours up and running.

Will be splitting between two rigs tomorrow adding another card. 

So motherboard can do 6 unpowered with a lot of messing around.  Looking back 5 with powered usb risers might have been way to go.  But I cant complain with them mining away dodge.

I am running 2 rigs with powered risers without plugging them into power without any problems. I have only 3 cards per rig though...

Another question. I'm running a AX1200i and some of the power supply's PCIe cables have two PCIe adapters coming off one cable. My 270's have two PCIe plugs. Can I power that card with the one cable or do they need separate cables for each plug?

H81 running 3 R9 7970s with NON Powered Risers.

These boards SPECIFICALLY have a power plug on the motherboard that you plug into that allows you to run unpowered risers.

Did you ask ASROCK? They made these board for mining.

Always use powered risers if you are using more than 3 gpus ,if not than non powered is also fine.

I second the use of powered risers for any rig with 4 cards or more. Especially with 7970 or higher cards. They pull way more than 200 watts per card.

Posted this in another thread, used 6xr9 270 and burned out the traces at the 24 pin power connector. So I would definitely use powered risers w/ this board.

here is a youtube where you can see a guy installing the H81 PRO BTC http://www.youtube.com/watch?v=WfqfEpanpig

Hmmm he seems to say DO NOT USE POWERED RISERS.

Did you plug in double molex?

 I sure did. I have 4 R9 290X running happy as clams with NON powered risers. All cables are cool and happy.

I would urge you to use the search function on the site and search on:

Asrock H81 powered risers

and see what you find, Youtube video not withstanding.

Yup, sure did

Also found this post on reddit
http://www.reddit.com/r/litecoinmining/comments/1vumlx/running_6x_r9_290not_the_x_asrock_h81_pro_btc/

My opinion of this board- its a POS, gonna go w/ another board and powered risers, preferably USB powered risers

I keep answering this, but this forum doesn't do a lot of searching :P   Just use USB risers and the board is fine. It's got great bios, it's CHEAP and has six working slots. Preferably my risers, if you want.

Has anyone had an issue with this board where after installing more than 2 GPUs the BIOS boot or the new Windows 8 splash screen won't load? With 2 GPUs everything works fine, however as soon as I add more no more BIOS boot!

Updated to the latest BIOS 1.30 but same issue. Is there a specific order of PCIe slots to install these into, currently only using the PCIe on non-powered risers.

Use linux

Thanks for that, I'll give BAMT a go later to see if any difference. But from what I'm seeing with this issue so far, the error happens before either Windows or Linux would load as there is no BIOS post screen. The first output from the card is when the Windows drivers loadup.

I'm wondering whether there is a need to have 1 card plugged into the x16 slot, although when I have the 2 working they are both plugged into x1 slots

No, you don't need a card on the board. I always install the OS and drivers with just one on the board, then after it all works I shut it down and plug all cards in via usb risers. I've got no problems with any of them so far.

Thats how I started this, put 1 card in and installed everything needed then turned off and plugged in the other 3 cards. Do you have a card in the x16 slot? I'm not going to put the card onto the board I have an x16 -> x16 riser that I can use

No, I do not have a single 16x- 16x or gpu mounted directly to a motherboard. you have some other issue.

Update.....Finally got this board to work w/ out powered risers, however, the verdict is still out on whether or not this board will hold up to 24/7 ops using the molex plugs....stay tuned

I agree these boards are absolute garbage. I've had two explode on me. sparks flying everywhere, burning out any peripherals attached.

Ive read on reddit thread to only use four because there are 2 molex into mobo and that

If more are used then something will melt

You should use powered riser for the 1x even though you have enough power. Because 1x only can transfer 25 watt

The way I understand it, actually 75W will be drawn through the 1x slot! That's because of the16x graphics cards usually draw 75W from the 16x slots. Since the card doesn't "know" it's attached to an 1x slot, it does not bother drawing 75W. When you take a look at the pci express pinlayout for example at wikipedia, you will notice that it's only the pins prior to the key notch, that are dealing with power. The rest is for data.

That's also why powered risers provide extra power to the PINS, not the 6+2 pin power connectors.

They actually don't. That is a MAXIMUM for the spec. Most cards I've tested draw 30-50 watts.

Good to know. How was the testing done?

what cards exactly? please post source of the |MAXIMUM SPEC|

Source? I've been doing this a very long time. Go out and get a multimeter and test it yourself, as I did. I've tested the current draw of every type of card I use.  people are looking for a source on something absolutely simple to test.

If you want to see pcie specs, google it. Each 6 pin and 8 pin connector has a design specification, as do the motherboard components, and every electrical device. Much easier to just test it.

hahahahahaha multimeter??!?!?!?!?! do you know why you shouldnt test psu (or anything else?) with a multimeter?

why proper reviews use laboratory equipment worth few grand?



please answer back

answer is yes..

Hey kid, do you know how to test current draw? It's not hard, and doesn't require lab equipment. When you try to be cute, don't do it with professionals.

Ive personally measured voltages and current of my psu.Then Ive read how stupid it is.Search about it on google.

(Hope you dont have kids.)

https://www.facebook.com/mlacom.si
2-3 rigs/day, only using asrock h61/h81 btc boards and ONLY 6x powered risers per rig. both molex connected on every mobo. seeing posts with too much power etc..go back to school

the reason with melted risers and broken boards:

-bad risers

-general noob mistakes, seen all and some are briliant fail.

-cross conected riser/main power from two different psus. use the same psu for riser and main gpu power on every card. dont power the riser from one psu and main gpu power from other psu. usually 3+3 cards or 4+2 cards

-main reason that all web is searching for an answer: SOME PSUS DONT ALLOW BRIDGE MODE. its a psu design, mostly cheaper psus has huge ripple when no mobo connected. just melted risers if you are lucky, more damage if you are not. wont list known psus here.

My 4pin amolex connected to mainboard is getting very hot( the connector by the 1x pcie) and the total power consum is increase more 200w. I had to turn off cuz it can be burn. It just happened this morning and i did nothing. I tried to change power supply. Change other board but its still happens. My other rig set up same but nothing wrong. Anyone help me :(