Topic: Motherboards: What Works w/Four or More GPUs? List Them - page 2. (Read 53356 times)

Still not clear to me. Is there a motherboard which can support  4 x HD7950 without having to short A1-B17 pin?

Hello
I don't think I am in a position to recommend you, I have been mining for only 1 month, this miner is the first one fully assembled by me (although I have 2 more (just 5830 on a small motherboard over a cardboard box which I use for testing because they are not cost effective (consumes too much power)).

That aside, I think that you should think what weights more for you, MH/s vs Power consumption or MH/s vs Hardware cost.

In my case is the first, because, for now, power cost is something I will have all the time, hardware is something I buy and I can use for other things besides mining, so I still have to test the performance of two 7950 vs four 7850 to tell you more precisely what is best in terms of power usage vs MH/s

However I will, in the end assemble 4 to 5 GPU per rig, because I think it's more power efficient, but still don't know which cards will I use.

the power consumption of the motherboard, processor and hard drive is quite significant, so the more GPU per computer the better, IMHO.
please if someone with more experience than me think different, comment, i will love to hear your educated point of view.

I'm starting to re-think the 4gpu on one motherboard scenario...

Based on pricing for mb/psu...would you recommend just buying two mb/cpu/psu (750w) and just building two systems instead of one?

I don't mind the extra work I just want to make sure and get the most performance out of them and it's starting to seem like putting more gpus on a single mb makes me have to cool them alot harder as well as the components being a lot more costly than components for 2/mb...

opinion?

Well..., I already had 2x 7850 I used with hashcat a lot, so I decide for this first miner stick with those cards, so I bought 2 more identical ones.

I'm building the next rig, they will have 2x 7950 now (and 4 x 7950 when I bought another PSU)

and I want to compare power consumption vs production because my measures doesn't match what I have read on the forum, so I will have to test both combinations and see which ones are more power efficient.

Money is about the same because 7850 costs half the 7950's.
will do the tests and post here this weekend (if my cards arrive on time )


Sure, give me time I will prepare something and post here.

With 4 7950s you should be making >2gh/s
?
Why only 1gh/s

Take pictures and write up a walk-through, please! :-)

Hi, yes I did it myself, it was time consuming to do it but I wanted something really strong, that I could fit in a rack later (its 44 cm wide for a reason ) and, if I need it, dissasemble entirely with ease (the entire case is screwed in the aluminium directly).
I cut the parts with a bench circular saw (from a friend, I don't own one, the only thing I have is a small bench black & decker driller machine) that was it.
I'm building the second one right now

Did you make that housing yourself? I like it, clean and space efficient. I wish I had tools to make my own.

Hello
WORKS:

Gigabyte GA-970A-D3, sempron 145, 1x 4GB DDR3, 1x HDD, Sentey 750W 80+ PFC  PSU

4x Sapphire 7850 1GDDR5 (dual cooler)

2 cards running on 16x powered risers (works with and without power)

2 cards running on 1x to 16x powered risers (only works with power) on 1x slots 2 and 3.

image:

Win7 x64 and GUIMiner BTC
This thing eats 440W from the AC outlet, and produces 1GH on BTC

Anyone want to update this?  I'm looking for a good mb to put four ATI 7950s in...

Thanks

WHAT WORKS
Motherboard Brand: Asus
Motherboard Model & PCIe Slots: F1A75-M LE - 2x PCIe 16x, 1x PCIe 1x, 1x PCI
Power Supply & Brand: MIST 400w & HP 475W
Number & Model GPUs: A6-3500 + 2x 5850 + 7970 + 5570
Extender Cables w/Molex Power?: One 1x-to-16x w/Molex for the PCI to PCIE adapter, one 1x to 16x extender, and one 16x extender.

WHAT WORKS
Motherboard Brand:MSI
Motherboard Model & PCIe Slots:big bang xpower 2. 7 pci express. 3x16 4x8
Power Supply Brand & Model: corsair hx 1000, upgraded to fsp aurum pro 1200
Number & Model GPUs:5 5870
Extender Cables w/Molex Power?:direct. Used 6 with x16 plain extenders to test. Ok too.

WHAT WORKS
Motherboard Brand: Gigabyte
Motherboard Model & PCIe Slots: GA-MA790FXT-UD5P 2x16, 3x1
Power Supply Brand & Model: Dual PSU setup
Number & Model GPUs: 2x5870, 1x5850, 2x 5830
Extender Cables w/Molex Power?: Extenders yes, Powered no.

Sorry, that was a typo.

AFAIK that has not been released yet.

How on earth do you have one ?

Please share a picture because I am dying to see my next mining cards !

Gigabyte 965P-DQ6 - Can't use the bottom x16 slot as it disables the 3 x1 slots... Everything worked once I figured that out. 2x 6950's and 2x 6870's

Asus f1a75-m le works with four (going to try a fifth in a few weeks when I get my pci-to-pcie adapter for my puny 5570). The four includes the APU. Only had luck with these in Linux, in Windows I only get two adapters. Running BAMT. Force onboard video. Running dual power supplies. Running w/out molex extenders, and did not need shorting for the 1x pcie adapter cable.

A6-3500 + 5850 + 5850 + 7970 for 1100 MH/s. (Bad performance due to driver/SDK because of the 7970).

EDIT: Typo

Are you plugging cards direct into the slots or using a riser? Also some boards are really picky and insist certain cards be plugged in certain slots, complaining that you need to populate certain slots first to enable crossfire/SLI, and refuse to boot further unless you do what it tells you to do.

Anyways, if you are using risers, you will probably need to short PCI-E presence pins. also make sure your risers arent defective or broken. Bending them a lot or plugging them in/unplugging a lot is very stressful on risers and can break the delicate solder points for the wires unless both ends are 1x physical width, which makes them effortless to plug in/unplug

I am going to be very precise here because there are other post on this Forum that say these boards work with more than 4 Cards and that is why I bought two of these F--cking things.

Both the Gigabyte boards I have, as listed below behave in the same manner.


Does not Work

Gigabyte 990FXA-UD5 V1.1 (Bios‘s F5 to F8) (MB Ser. No’s 115100014366 & 115100014364)
4 GB Ram 1333Mhz (1 Stick)
AMD X2 260
Corsair 1200W
80Gb HDD
Xubuntu 11.04 - 64 bit
Drivers 11.6
SDK 2.4

Does not ever see more than 3 Cards. (lspci, aticonfig --lsa)
Will run 3 Cards direct off  PCIE x 16_1 , PCIE x 16_2 , PCIE x 8 These are the only slots you can populate using double width cards inserted directly into the slots.
Will NOT run the same cards on the same slots when connected with 16 x 16 extender (Powered or un-powered)
Will run same cards and extenders in PCIE x 16_1 , PCIE x 4_1 , PCIE x 4_2
(appears to be a Latency issue, no adjustment for PCIE Latency available in Bios’s listed above)

Shorting presence pins, 1 x 4 extenders, etc etc, nothing seems to work.

_________________________________________________________________________


Does Work

MSI 990FXA-GD80   (MS-7644 V2.2)  (Bios E7640AMS V11.5)
4 GB Ram 1333Mhz  (1 Stick)
AMD X2 260
Corsair 1200W
80Gb HDD
Xubuntu 11.04 - 64 Bit
Drivers 11.6
SDK 2.4

All physically exactly the same components as above on the Gigabyte 990FXA-UD5 V1.1 board except the Motherboard changed to the MSI 990FXA-GD80 board.

4 Cards (AMD 5850) on 16 x 16 extenders (un-powered) connected into all four PCIE 16 way slots on the board. No presence jumpers.  

Changes required:- PCIE Latency set to 96 in Bios.

All cards recognised immediately after boot by:- sudo aticonfig --lsa

Less than one hour after walking thru my front door with the MSI board I was mining on 4 Cards @ 393 M/H on all cards, exactly the Hash rate I was getting per card with 3 Cards on the Gigabyte board
                                                           --------------------------------------------------
Edit:- now 1 day later, I have 5 x 5850's mining on the board. Fifth card is on slot marked as PCI_E3 using 1 x 4 Extender (Powered) and A1 jumpered to B17 on the Slot. Same routine as before, recognised by "sudo aticonfig --lsa" immediately after boot. no screwing around!
                                                           ---------------------------------------------------
So, if you are a Noob, and you have a deeply masochistic streak, you obtain real gratification from hours of self flagellation and stress, then the Gigabyte 990FXA-UD5 V1.1 is tailor made for you.      
On the other hand, if you want something that simply works “out of the box” spend the extra bucks and buy the  MSI 990FXA-GD80   (MS-7644 V2.2) In fact buy anything other than a Gigabyte board even if you simply want reliable USB Boot!
With the benefit of 20/20 hindsight, having bought the two Gigabyte 990FXA-UD5 V1.1 in January and since spent 100‘s of hrs searching for remedies. While all the time 25% of my Hash power is un-usable sitting in the cupboard and 50% of the remaining hash power is off-line about 3-4 hrs a day while I try unsuccessfully, various fixes to make the Gigabyte board see more than 3 cards.

The extra bucks is something I would have paid happily!

What Works:

Motherboard: MSI-790FX-GD70
Power Supply Brand & Model: OCZ ZX 1250 Watt modular Power Supply
Number & Model GPUs: four 5850s... now 3 5850 + 1 5970
Extender Cables w/Molex Power?: none, but you can do them since 4x 5850 runs really hot and if you OC prepare to have brunt out fans in a few months, on 70+% speed for 24/7. I added spacers inbetween the card ends to get air in. I suggest a spot fan or a extra fan blowing on these also, drops temps 10-15 degrees.