HELP - Will it work???

[Jilixi]

Hi, I would appreciate any help on the matter

I got some stuff on the way for scrypt mining the setup is as follows.

Motherboard: Gigabyte Z77A-GD65 http://motherboard.findthebest.com/l/614/MSI-Z77A-GD65
GPU: 1 x 7950 Sapphire http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1157&pid=1551&psn=&lid=1&leg=0
       2 x 7950 Sapphire http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1157&pid=1841&psn=&lid=1&leg=0
       2 x R9 x280 Sapphire Vapor-x http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1227&pid=2024&psn=&lid=1&leg=0
PSU: 1 x Seasonic 1250 Watt Modular http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109
        1 x XFX 850 Watt Bronze Modular http://www.newegg.com/Product/Product.aspx?Item=N82E16817207011
CPU: Intel Pentium G2020 http://ark.intel.com/products/71070/
RAM: 16 GB
Risers: 6 Unpowered

The 850W Psu is supposed to run 2 cards and the motherboard, the 1250W the 3 (maybe 4) other GPU's, All will be undervolted and clocked until stable. Stored in a outside temperature storage unit (Very good location)

Now question is, will I be able to run all those different GPU's on the same motherboard without problems? I have almost everything except the 1250W PSU and 2 x280 GPU's
I heard something about setting up both PSU's on the same ground or connect the ground on both, any way someone can explain how? or link me to a page that shows it?

System is running Xubuntu 13.10 on a USB works without a problem, and 3 of the cards are actually hashing but since they are all 7950 and I want to add R9 x280 to that I would like to know if it would work?


Would appreciate any help and sorry for spelling and such, I am kinda in a rush

Thx in advance
Jilixi

[MineNerd]

I would highly recommend using powered risers for that many cards on one motherboard.

[Jilixi]

Why powered if they are getting the power from the PSU?

[balanghai]

Your Mobo could only handle 75w/pci-e so come to think about buying powered risers so you won't fry both your Mobo and GPU.

[Jilixi]

So the GPU drains power from Pci slot as well as PSU? so just plug that molex cable to the psu as well?

[LiteMine]

popcorn 

Mining 101: Use powered risers or burn your house down

[balanghai]

The 4,6,8-pin is different from the Mobo Load. Having 3-4 GPUs will give high current on the pci-e bus, and as you might know that the buses are only hair thin and can easily fry the mobo and damage your gpu as well.

[Jilixi]

So might as well go with all powered then?

[balanghai]

Yeah, have it all powered also it makes the airflow really good so set it up and earn BTC0.05-0.1 per day. Happy Mining!

[LiteMine]

You need the mining thread: https://bitcointalk.org/index.php?topic=117221.0

Lots of references to this issue there, my understanding is you can leave 2 or 3 safely un-powered.


Is that a joke? All powered creates a cable mess and PSU might not have that many molex, but didn't check.

[Jilixi]

But overall its good? and mixing 7950 and x280 shouldnt be a problem right?

[LiteMine]

In my experience, you can mix cards that have the same -g parameter. I couldn't get 7970's to work at top speed with 7950's because of this. I don't have a x280, so not sure.

That mining thread is pretty dead these days, since it wasn't really profitable to build miners over the last few months.

And clear that CMOS if it doesn't recognize all the new cards upon install.

[balanghai]

The cable mess is not an issue if you know how to tidy things up.