Bitcoin Forum

Hello,

I have some hardware problems to connect all my card recognized by the system ( Windows 8.1 Pro/Core ).

Only 2 have been recognized, one time it's work with 3 card.

Here my hardware ;

ASRock B85 Anniversary
Intel Pentium G3258 (3.2 GHz) FSP AURUM 1200 Pro 80PLUS Gold
 + with an other power supply  850W --> Connected in syncro with ADD2PSU
Corsair Force Series LS 60 Go
G.Skill NS Series 4 Go DDR3 1333 MHz CL9

Graphic cards :

6 X AMD SAPHIRE RADEON 290X
 
5 connected with a cable Riser PCI Express 1 x to 16x with molex connector

1 connected with a cable Riser PCI Express 16 x to 16x with molex connector

Drivers is installed.
Motherboard graphic integred is desactived.
The rig can run 6 graphics card with Windows 8 but don't recognized 4  or 3 of them. The problem is when I change from the port with the cable riser
Its change all time to where I have to put the cable for my monitor from the port 1X ! Also the 16x to 16x never recognized by the way.

Maybe I should try dummy plug on all my card because the motherboard is not MULI-GPU ? Or change the cable riser to buy a more expensice, the one with USB ?

Please if someone who knows what I have to do for the next. Thanks.

Have you asked anyone else who uses this moterboard?

To get 6 on one motherboard my guess is you need to use powered risers.  Even if the motherboard has 2 molex to power the PCI slots for GPU's. In my experience it was not enough power.

But were talking like over a year ago when I was building them.  So it could have changed.

pm me on freenode, same nick as here.

that motherboard isn't that good  for 6 cards, there is only one 4 pin molex, you might overload those pci-e, you need power risers

anyway the trick to make windows recognize it, is to add one at time, and let it search for the drivers, the restart + shutdowwn and repeat

When I said rise cable with molex connector I means power riser. So yes I got it. I Check for in Google to find problem with the motherboard but difficult to find who have the problem. So maybe I need to change motherboard but the motherboard have 5 port x 1 and 1 at 16x. Normaly it have to work no ?

Depends on the behavior of the pci-e ports. It really suxx to find the correct mobo for 6 cards, especially with windows. No problem with linux most of the time.
BTC-pro mobo is pretty okay, and cheap too.

BTC-pro mobo still needed powered risers when I used one long ago to get all GPU's working.  Maybe my insensitivity was to high.  But 2 molex just did not do it.

There are some great powered usb risers.   That is what I would use if i was building a rig ever again.

Oh then I should buy and try with the mobo BTC-PRO and buy USB Power Riser, ;)

What about the Dummy Plug ? No one say something.

Oh thx for your answer you help much ! Maybe its just about the mobo. Thx all

I never used a dummy plug but it's been so long I might have had monitors on my rigs. 

The BTC PRO is not necessary the best mobo.  I would get some more current advice in altcoin forum.  BTC PRO was a pain when i used it.  But I also didnt have powered risers on them. 

yeah but it is not made for that, it could break due to heavy load of current, you could have bought h81 pro btc, it is made specifically for mining, with two 4 pin molex

i used it to power six cards no problem


are you sure? in my case i did not use any powered molex

 because two molex can provide 132w of each plus you have 25 w x 5 pcie x 1 and 150 from x16

so a total of 132 x 2 + 125 + 150 = 539

to this you add the pci-e from psu who should provide additional 75+150 for each cards(let's assume a gtx 970)

in the end you have a basee of 539 + 225(for each cards, this is more than enough

You may require to short the PCIE pins (A1B17 or A17B1?) to make the system aware of the cards?

And use powered risers. And get these hold down clips.  http://www.miningcryptocurrency.com.au/store/p4/RiserSafe_By_the_Inventor_Patent_%28Pending%29.html     

I had an issue similar to this and my problem were some of the cards were in idle mode as the MB though no monitor was connected.

My answer that fixed this was to buy a few dummy plugs which tricked the MB into thinking a monitor was connected, there really cheap on amazon or fleebay

Try this: plug in all your 6 GCs, then run the install CD that come with the GC.

hmm, that looks nice  8)

old post but i wanna confirm that 

ASRock B85 Anniversary  runs 6 gpu's

if it s not working it s because you have to short the pcie 1x pins, for the card will be detected

list of intel board what run 5 or 6 gpu's
https://proxy.crushus.com/bitcointalk.org/index.php?topic=1284889.60

For me, I usually undervolt and underclock, so I do not use too many powered risers. For the Pro BTC, I use 2 to 3 powered risers.

Do you gain hash rate by under volt and under clock?

what is the point to under clock ?  you get less speed

i overclock it but not at max, don't wanna kill my gpus
running 6 x 380's at1080 on 1200w
and 5x 380's on 1000w

well you can underclock memory to allow for gpu overclock without rising power usage or temp.
you can also underclock if your gpu is overheating or unstable.

the real point for it is to maintain the hot level at minimum, you have fresh and more cooled card with it, it's good to underclock in the summer, in the winter you can avoid it

but this only cut it if the ratio is the same between consumption and earning, not always the case

For the AMD R9 390, we can use the 1250 MHz instead of the 1500 MHz. The hashing speed is not affected.

Good info in here, thanks for the tips.

If you do not overclock to over 1120 MHz in the core, the memory speed can be 1200 MHz, using 98% of memory controller.

That can be mobo fault.

just to say the ASRock B85 Anniversary, is not good for 6 gpu's, 5 is ok but not six

the computer is not stable i always have trouble with it, got crash at lease 1 time a week (not overclocking probleme)
computer freeze or half freeze , you can acces some stuff but got error's or program won't load and some are freeze)

specially not compatible with 6 x r9 380
not able to get in windows after you install the last driver, if you do, you get hard disk error's and windows service what crashed
i tried win7 the worst one never got in windows after 6 graphics drivers loaded, and win 10

it s actually the last pci-e connector ho makes the troubles (is it share with the sata's connector?)

i switched the gpu's with my other ring, 2x r9380 + 4x r9 270, it s working under win 10   but it s not stable
sometime after crash i m not able to boot again, i have to restart  the computer with the last one unpluged, and reboot again with the last one pluged  ???