Topic: Building 6 card rig for alt coin, where to get powered risers? (Read 2186 times)

I thought i would put in my 2 cents

I have 2 rigs that use 6x gigabyte 270s. Both use Pro BTC motherboards (one is a h61 and the other h81).

5 cards work off the bat in windows 8.1 but you will have to manually force windows to install the right driver to use 6 cards. Google that

I was using two PSUs per rig (platnum rated 90% efficiency) and the draw at the wall was 1200watts

DO NOT use a 850 watt PSU for a 6 card rig

The dude who pointed out having twice the PCIE power connectors is not worried about the extra power drawn by having twice the connectors. Hes pointing out you wont find a PSU that can support 12 total connectors. I was using a RM1000 and that has 8 in total so you will have to make or buy adapters to solve that problem

If you think you can handle it then just buy a cheap PSU (450watts) for the motherboard and system. Then buy a 1600-2000 watt server PSU from ebay for 30 quid and solder PCIE connectors to it. Boom, you have 2400watts of power for 60 quid.

Both rigs do 2.68MH each and both draw 1200watts each. Build them in open air cases, you can find designs anywhere.

The pro BTC boards do not need powered risers. They have 2 molex connectors on the motherboard that add power. 

Hi, so what did You build in the end?

Was getting 270 really better than 290?

You probably want to go with a 1400w or more. Lepa 1600w is a nice one.

recommended watts for 2 7950 and 3 280x??

yea that 1200 LEPA will be my first choice if i just decide to go with a 5 card build. It's also in stock, for now :\

What he said ^.

The 270 reg is basically a 7850 with some awesome ram.  It won't pull more than 150w, guaranteed.  It only has a single 6 pin.  

Also, stay away from EVGA PSUs.  Seen plenty of complains about them.

The 2 best bang for buck PSUs out there right now are the 1200w LEPA units (rebranded Enermax) or the XFX Core Edition 1250w units (rebranded Seasonic).

You could also always go with Corsair, Seasonic, Antec, and Enermax.

Also, why combined 1900w for 6 270s?  That's only ~800w + system maybe another 200.. you're looking at only really needing a single 1200w unit comfortably powering everything.

It's my fault for recommending them everywhere lol.

yea it's crazy, i was checking the quantities and it seems like all the 270s are selling out as we speak. I wonder when new stock will come in and if prices on the 270 will be the same

They do vary in power draw but not by much. I would imagine that the gigabyte unit with 2 plugs is a lower binned graphics processor than the 270x counterpart. The 270s are essentially just downclocked 270x's.  2 connectors just means it has the potential for more power draw. Will it draw more power? I honestly don't know, I think it will.  Testing it is really the only way to go.  Personally the 270 non-x is now my best bang for the buck card, especially considering the crazy price hike on the rest of the AMD lineup.

sometime after the new year I believe.

why is 2 6-pin connectors bad, as opposed to one? (nevermind i think you already answered this before i was able to reply)

Just some math comparing the two cards. And since you say that the 270 uses less than 200 watts then that gives it an even greater advantage over the 280x

2,250 kh/s - 5 x R9 270 = $900  

2,250 kh/s - 3 x R9 280x = $1260

I actually have spare motherboard / cpu / HD / ram / 650w PSU's I could use so I don't need to spend money on any of that stuff.. Only thing is the 650w psu are rosewill brand so I don't know how that will hold up.

I respect both of your advice, and the only way to know for sure is to test it out myself (ordered a kill a watt meter for this purpose), cus i think cards vary in power draw between brands.

I don't know if the gigabyte models will draw more power, technically they can because they have two pci-e power connectors.  I do know that the 850w I have is perfectly suitable and within a very good efficiency range for 5 cards.  I could not get 6 cards to work ever.  Seems to be a problem with AMD drivers or similar.  I've had several friends try but they never succeeded.  I understand that MisO69 is a full member and I respect his opinion but I am going to have to disagree on the power supply.  If you got 6 cards to work on that one board you will still not need a bigger power supply then 1000w to be safe. The system would run at about 850w or so depending on power supply efficiency. This again is using my r9 270s as a guide.  I have the MSI, Sapphire, and ASUS models.  They all have 1 power connector. They are great little cards, although the MSI by far outdoes the rest. At 1000/1500 with powertune +0 it will do ~420khash/s on i 17.  The sapphire models need i19 to reach that and the asus seem to need i 18. Also the Sapphire seem to run cooler out of all of them but they are also shorter cards than the rest.

True that one PSU is cheaper and will produce less heat than two. The heat that the 6 cards produce will be astronomically more than the PSU so heat from them is really a non issue imo. My recommendation is don't go cheap. If you do you'll be sorry in the future. True, that 1600w power supply will likely be high quality, more than enough and the two I recommended combine total of 1900w overkill. But that 300Watt is a nice buffer. Two power supplies also make it easier to put a 6 card rig together. One on each side and the PCI-e cables reach no problem.


The price difference between the two cards is insane. If you can really get 450Kh/s with that R9 270 (Gigabyte) GV-R927OC-2GD. Thats the one in the litecoin hardware comparison. I would be curious to see if you can get that kind of performance from the cards. If you can then forget the 280x all together and build a bunch of 6 card rigs using these with 850w primary PSU and a 750w secondary PSU. That may be cheaper than a single 1600w.


So when do your cards arrive?

I may just get the EVGA 1200w though, it's only $50 more and i may want to upgrade the cards in the future if i come by some cheap. I definitely understand the importance of the PSU, i've built a few rigs in the past.

In my research I feel it's safer to just use powered risers, only a few bucks more and at no disadvantage.

You're right about it having 2 dual 6-pin connector, could you explain why that is a bad thing?

btw, holy crap the gigabyte 270 already out of stock, there were still 70 yesterday at newegg.

Get the 270s, non x. They won't use 200W each, and I haven't had to use powered risers, just have normal ones. Also 1 good 850w gold or platinum 80+ power supply should do you well. Amd CCC will only pick up 5 cards, don't waste your time trying 6. DON'T CHEAP OUT ON THE POWER SUPPLY!! 850w is minimum. Try to get the msi or sapphire 270 non-x because the gigabyte appears to have two pci-e power plugs.  My MSI card draws about 150w out of the wall with a 80+ bronze power supply, with the gold they sip power at about 110w or so. I do 420ish khash/s on the MSI at i 17.

BTW with my setup the cost would be about $1300ish.

EDIT: http://pcpartpicker.com/p/2suZd

This is pretty much my setup minus 3 video cards, pc partpicker won't let me add them.

The 5 cards on this setup run about 650w out the wall. Each at 420 khash/s means 2.1 mhash/s

thanks man i really appreciate it. I am quite technically skilled, and stress is expected.

I actually have bookmarked a lot of these troubleshooting issues while i was researching and came across them by accident.
I guess the 6 card thing will be an issue, is it just certain motherboards?

As for the PSU, that's too bad because I think one psu is cheaper and produces less heat? i was really hoping to just find a 1600w, because I want my rig to look clean.
Speaking of which, thanks for the link to the preconstructed frames, will definitely order from them. Good to know someone offers such a product for someone who can not hammer a nail straight if his life depended on it, at the price that it would have cost me to make one myself.

oh yea, will i need the extra long risers? or just the short ones for these specific frames?

Regarding the 280x, is it really worth it even though its more than twice the price?  $420 vs $180?

I had these questions a few months ago and could not find any answers online, or it was difficult. Its like everyone is keeping rig building a secret. I just hope for your sake that you have technical knowledge. Otherwise expect much stress.

So for risers you can order them with paypal from these places. Get extras if your are thinking of building more rigs.
http://www.hashratestore.com
http://www.cryptocables.com/

For when you are scratching your head trying to figure out why the fuck my motherboard doesn't see all 6 of my cards?
http://framer99.blogspot.ca/2013/11/multi-gpu-machines-and-pcie-in-band-vs.html

As for your question about power supplies. There is really only one answer. Get TWO. The main can be as low as a 1050watt corsair or seasonic. The secondary an 850watt. One of those stores I mentioned above sells cables that allow you to link two power supplies together and turn both on with the motherboard power switch. Alternatively a mod can be done to the power connector.
http://www.overclock.net/t/15751/info-can-i-use-two-power-supplies-with-one-computer
There is a sports model as well.
http://www.add2psu.com/

The last thing is getting windows to see all 6 cards. This I have not had much success. I have read quite a bit about it and believe its a simple thing that most people don't get because they are not technical enough. I read a lot of posts about Windows 8 and downgrading to 12.6 drivers. blah blah.. There is one post that I found that I think may solve the problem. I just haven't had a chance to test this yet. Here is what the guy said..
"To fix this problem I manually go into the registry (regedit), and change all "EnableULPS" entries to 0 instead of 1... Fixes the issue for me Cheesy"

Oh, when you get sick of looking at the makeshift frame you constructed for your rig you may want to check out these guys.
https://openrigs.com

Oh.. just re-read your post and noticed that you got R9 270 cards. I suggest you send them back and get R9 280x. They hash at 740Kh/s. Get Sapphire dual fan cards if possible.

So, i've been keeping tabs on bitcoins for 2 years now, missed that train and finally decided that I want to get into altcoin mining.

I was following this guide http://www.coinminingrigs.com/how-to-build-a-6-gpu-mining-rig/#comment-36695
but am looking for second opinions.

Since the 280x and 290x are way overpriced now. I went ahead and already ordered, and am awaiting delivery of six, gigabyte R9 270 ($180). I figured I might as well bite the bullet cus they are selling out as we speak, i could always return it if I test one and it doesn't work out.

So I have just three questions:

1) Is this really the best card available now initial price to hashrate wise? or would you have gotten the slightly more energy efficient 280x at $420?

two, R9 270 producing 900 kh/s drawing 400w vs a single R9 280 producing 750 kh/s drawing 300w. Maybe I should have gotten the 280x.  Havent even received the units and i'm already feeling buyer's remorse haha.
The reason I didn't automatically go with the 280x is because all the 1600w PSU's are out of stock.
I guess #1 isn't really a question and I'm just looking for someone to reaffirm my purchase. lol.

2) Can someone recommend a place to get powered risers that wont blow up in my face? Was thinking about ordering from here:
http://www.ebay.com/itm/PCI-E-16X-to-1X-Adapter-Riser-Card-Flex-Extension-Cable-w-Molex-Power-Connector-/181285248039?pt=LH_DefaultDomain_2&hash=item2a35715c27

3) Is this 1300w PSU a good choice? http://www.bhphotovideo.com/bnh/controller/home?O=&sku=1012719&Q=&is=REG&A=details
or should I wait for the 1600w LEPA to be available again, in case I want to upgrade the cards in the future (anyone know when?).
 I'm not in a hurry since I have other computers I could temporarily set these cards in.