My big mining rig project
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[quote name=“Kagemusha” post=“4395” timestamp=“1368963725”]
Where are you putting the rig? If its in an outbuilding/shed have you considered making an exhaust manifold from the fans with large bore ducting to the outside world? That lot looks like it’ll kick out a serious amount if heat!
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Excellent question. I have a cellar, a large room in the basement that I share with a shop that stores some promotional materials there. It’s subterran and has a window that opens to the outside just below the ceiling. Even with the drier in the next room running on full blast, it’s always cold in that room. Right now I have half a dozen machines running there and it’s not gotten even remotely warmer in there.The rig will be setup so it blasts against the brick wall near the window (with a space between rig and wall, have to find the right distance once the rig is running). If heat get’s worse, I can replace the window with a lexan sheet and place fans in that to get the heat out of the room.
With one rig I don’t forsee any problems, the room is large and cool even in the hottest summer. I will keep an eye on temperatures though as I want the rig to run 24/7 for a very long time.
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Nice. If you do run into problems and need some help with heat loss/gain I can run some quick calcs for you.
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[quote name=“Kagemusha” post=“4398” timestamp=“1368965477”]
Nice. If you do run into problems and need some help with heat loss/gain I can run some quick calcs for you.
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What kind of claculations? :) Any helps is always very wlecome. -
HVAC calcs. Basically taking into account building fabric, heat gain from equipment, heat loss through fabric of building, air flow, air temperature. Desired air temperature. Ill be able to calculate if you need/want any supplementary cooling/extraction.
I occasionally need to do calcs for rooms/buildings that are to house UPS and batteries/relays. Most other equipment I deal with isnt temperature sensitive.
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[quote name=“Kagemusha” post=“4402” timestamp=“1368968359”]
HVAC calcs. Basically taking into account building fabric, heat gain from equipment, heat loss through fabric of building, air flow, air temperature. Desired air temperature. Ill be able to calculate if you need/want any supplementary cooling/extraction.I occasionally need to do calcs for rooms/buildings that are to house UPS and batteries/relays. Most other equipment I deal with isnt temperature sensitive.
[/quote]Sounds interesting. What numbers you need to do that? :)
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Total wattage of system/power supplies inc lighting and other sources of heat e.g 5kW
Room construction/material e.g concrete
Room dimensions e.g 3000x3000x2200 (lwh). Are any walls external?
Nearest city, for environmental data
Required room temperaturePM me the information if you want. Should be able to do it tomorrow.
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Its a pity all that ducted heat can’t be reused for something else.
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[quote name=“pyxis” post=“4424” timestamp=“1368982482”]
Its a pity all that ducted heat can’t be reused for something else.
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Yes, I agree. Wish There was a heat exchanger so I could feed it into some heat storage which in turn could be used to heat water for daily use. -
[quote name=“ChristianRiesen” post=“4426” timestamp=“1368984090”]
[quote author=pyxis link=topic=387.msg4424#msg4424 date=1368982482]
Its a pity all that ducted heat can’t be reused for something else.
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Yes, I agree. Wish There was a heat exchanger so I could feed it into some heat storage which in turn could be used to heat water for daily use.
[/quote]I don’t think it would be possible as the losses you’d incur would be too great. Interesting idea though. I did do some quick reading as I thought how do submarines handle heat generation/storage. Seems they just use the hull as a giant heat sink as they produce far more than they need.
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That looks amazing. I can’t wait to see some numbers on how well it keeps the cards cool. Nice work.
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[quote name=“steganos” post=“4804” timestamp=“1369113473”]
That looks amazing. I can’t wait to see some numbers on how well it keeps the cards cool. Nice work.
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Thanks. I planed on making extensive tests. As soon as I have the risers I can finish the design and send it to be laser cut. While that happens I can do some open air testing to get good numbers of a before and after state. -
I’m sorry no one has told you this, but:
The Z77A-45 can’t hold 7 cards. It has 7 slots, but can’t do 7 cards. It does 5 maximum without a presence short, and 6 with a short on the middle X16. They’re great motherboards, but 7 is a no-go.
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[quote name=“Benny” post=“6352” timestamp=“1369489940”]
I’m sorry no one has told you this, but:The Z77A-45 can’t hold 7 cards. It has 7 slots, but can’t do 7 cards. It does 5 maximum without a presence short, and 6 with a short on the middle X16. They’re great motherboards, but 7 is a no-go.
[/quote]Hi Benny, Is there a board that can take 7 cards?
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I honestly am unsure what boards, if any, can hold 7 cards without BIOS or motherboard conflicts. I am certain they exist, but I really can’t speak as to which boards can do it, and are cost-effective. I’m sure something like the MSI Big Bang series can do it, but its cost-prohibitive.
Really, the best you can do is a 5 or 6 card setup based on the MSI-Z77A-45, or a similar board. If you keep adding GPUs, you’re going to offset the CPU/RAM/ect savings by more money on larger PSUs (assuming you don’t use a dual setup), as well as motherboard costs.
The last time I did a CBA on it, you may save 3-4% of your costs on a 6-card presence shorted Z77A, assuming it works properly.
IMO, going with 4 cards is probably going to be optimal for most scenarios. The more you get, the more PSUs/bigger PSUs, which kill any sort of advantage of more cards per rig. RAM, CPUs, and HDD space are the cheapest parts of a rig, whereas GPU and PSU are the most expensive - which mostly correlate with the higher prices.
FWIW, I have 2 Z77A-45 rigs that have 5 cards each… Probably one of the first people to use the configuration for 5x7950. Its nice, but the power draw is insane. Much easier to simply get a 4x PCIE board (Z77A-41, or a MicroATX) board, save $50, and deploy a 4x setup of WF3s or another GPU that will get you ~2.6 MH on one rig.
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[quote name=“Benny” post=“6352” timestamp=“1369489940”]
I’m sorry no one has told you this, but:The Z77A-45 can’t hold 7 cards. It has 7 slots, but can’t do 7 cards. It does 5 maximum without a presence short, and 6 with a short on the middle X16. They’re great motherboards, but 7 is a no-go.
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Thanks for the input. Can you be a bit more specific? According to everything I can find on the topic, the board has all 7 slots wired and all 7 can be used at the same time (using them all as x1 only). Is there something you can link me to why this shouldn’t work? -
[quote name=“Benny” post=“6370” timestamp=“1369500205”]
I honestly am unsure what boards, if any, can hold 7 cards without BIOS or motherboard conflicts. I am certain they exist, but I really can’t speak as to which boards can do it, and are cost-effective. I’m sure something like the MSI Big Bang series can do it, but its cost-prohibitive.Really, the best you can do is a 5 or 6 card setup based on the MSI-Z77A-45, or a similar board. If you keep adding GPUs, you’re going to offset the CPU/RAM/ect savings by more money on larger PSUs (assuming you don’t use a dual setup), as well as motherboard costs.
The last time I did a CBA on it, you may save 3-4% of your costs on a 6-card presence shorted Z77A, assuming it works properly.
IMO, going with 4 cards is probably going to be optimal for most scenarios. The more you get, the more PSUs/bigger PSUs, which kill any sort of advantage of more cards per rig. RAM, CPUs, and HDD space are the cheapest parts of a rig, whereas GPU and PSU are the most expensive - which mostly correlate with the higher prices.
FWIW, I have 2 Z77A-45 rigs that have 5 cards each… Probably one of the first people to use the configuration for 5x7950. Its nice, but the power draw is insane. Much easier to simply get a 4x PCIE board (Z77A-41, or a MicroATX) board, save $50, and deploy a 4x setup of WF3s or another GPU that will get you ~2.6 MH on one rig.
[/quote]What kind of power supply do you use? I run out of power on the 1200W supply I have with 3 cards already…
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I only run 4x cards, but use 1250-1300w rated gold/platinum PSUs… Seasonic, Rosewill, ect.
You shouldn’t be pulling 1200w on a 3x7950. You should only be pulling about 900-1000w at maximum.
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I’m using a 1500watt thermal take psu, pulling 1000watt on 4 X 7950’s no overclocking, with overclocking its pulls just under 1200watt.
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[quote name=“Benny” post=“6503” timestamp=“1369520909”]
I only run 4x cards, but use 1250-1300w rated gold/platinum PSUs… Seasonic, Rosewill, ect.You shouldn’t be pulling 1200w on a 3x7950. You should only be pulling about 900-1000w at maximum.
[/quote]I’m pulling just about 1000 with 3 cards, but that is on the socket. I haven’t tried with 4 cards on one PSU. From my experimentations, one additional card sucks down roughly 300 W.
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Was thinking about the drawing you showed me, have you checked that the extension cables are long enough to reach each card (since you will have alot of space between them)