My big mining rig project
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[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)
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Holy canola batman, I just came across this nugget in my research on trying to figure out what my board does (and doesnt) do:
[url=http://www.tomshardware.com/reviews/z77-express-ivy-bridge-benchmark,3254-26.html]http://www.tomshardware.com/reviews/z77-express-ivy-bridge-benchmark,3254-26.html[/url]
[quote]MSI saves one of the Z77’s PCIe 2.0 lanes by omitting the PCIe-to-PCI bridge needed by certain competing boards to support legacy slots, and then uses it on a PCIe-based network controller. Only three PCIe 2.0 lanes remain to feed four x1 slots, so MSI decided to connect both of the center x1 slots to the same pathway. These can’t be used simultaneously. Appearing to be a blatant move to artificially bolster the board’s spec sheet, we think MSI should have simply left off the x1 slot immediately below the top x16 interface. The GPU coolers of most high-performance graphics cards cover that slot anyway.[/quote]
So no wonder I got weird problems as soon as both middle plugs were in.I think I will see if I can get a different board. Really want this build to be able to run 7 cards. Otherwise I have to go down to 6 and that doesn’t sit right with me. I might as well just create 4 card rigs then.
As for the cables, I went with what the people making them told me. Big mistake. The cable are short in any which way you slice it. I will have to change the model some more to compensate. Now that I have the risers to play with, and the second power supply, I can also measure all cables and hands on experience with how flexible the risers are really (hint, not very much…)
My quest continues.
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[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]Question here… can a Antec High Current Pro HCP-850 handle 5X7950 ? I mean to be used only for the GPUs?
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[quote]Question here… can a Antec High Current Pro HCP-850 handle 5X7950 ? I mean to be used only for the GPUs[/quote]
7950s run about 200 watts a piece. short answer, NO :P
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[quote name=“fher98” post=“7263” timestamp=“1369689207”]
[quote author=Benny link=topic=387.msg6370#msg6370 date=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]Question here… can a Antec High Current Pro HCP-850 handle 5X7950 ? I mean to be used only for the GPUs?
[/quote]For 5x7950, you want at least 1500w.
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[quote name=“Benny” post=“7289” timestamp=“1369696637”]
[quote author=fher98 link=topic=387.msg7263#msg7263 date=1369689207]
[quote author=Benny link=topic=387.msg6370#msg6370 date=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]Question here… can a Antec High Current Pro HCP-850 handle 5X7950 ? I mean to be used only for the GPUs?
[/quote]For 5x7950, you want at least 1500w.
[/quote]Why? each 7950 consumes 180w MAX.
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The max draw is officially 200W with some clocking though it goes higher. And then at the socket it draws more, a lot. I get with 3 cards a draw of 1000W on the socket. The power supply still has reserves, but more than 4 cards on a 1200W PSU I wouldn’t risk. Even though the supply says 1200W, not all of that is available on the rails used for the PCIE. Your mileage may vary.
I’m rethinking my project because 7 cards seems to be almost impossible to pull off, because of crappy board support. I could do it but then pay more for the board then a new GPU would cost. So now I redo it as a 4 card rig, so I would build two of these and see how that goes.
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[quote name=“ChristianRiesen” post=“7398” timestamp=“1369725656”]
The max draw is officially 200W with some clocking though it goes higher. And then at the socket it draws more, a lot. I get with 3 cards a draw of 1000W on the socket. The power supply still has reserves, but more than 4 cards on a 1200W PSU I wouldn’t risk. Even though the supply says 1200W, not all of that is available on the rails used for the PCIE. Your mileage may vary.I’m rethinking my project because 7 cards seems to be almost impossible to pull off, because of crappy board support. I could do it but then pay more for the board then a new GPU would cost. So now I redo it as a 4 card rig, so I would build two of these and see how that goes.
[/quote]Maybe not 7… but 5 maybe? What mobo would handle this many GPUs nicely?
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[quote name=“ChristianRiesen” post=“7398” timestamp=“1369725656”]
Even though the supply says 1200W, not all of that is available on the rails used for the PCIE. Your mileage may vary.
[/quote]Most half decent supplies will deliver ALL of the stated wattage to the 12v rails that the pcie uses. My seasonic x1250s for instance deliver 1248w to the 12v rail + 150w to the 5v rail (1400w total). It’s also worth noting that the wattage specified is what it can deliver to the components (output wattage) rather than input wattage (at the wall). An 80+ gold psu is around 87-92% efficient so if you loaded it to 100% you’d pull over 1500w at the wall and still be within spec. These supplies have headroom built in too so I wouldn’t be surprised if you could pull 1600w at the wall before the ocp kicks in.
Now for the disclaimers… The CPU also takes it power from the 12v rail as do hdds and cd-roms etc (that’s why I use ssd). The CPU never ramps up for mining though (unless you gpu mine too but that’s a waste of money IMO). Also, as with most things, heat is an issue. Again, most decent supplies are rated at 50degrees ambient but some lesser supplies my only be able to supply the rated power at 30 degrees which is VERY unrealistic.
Just my 2ftc…
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[img]http://imageshack.us/a/img46/4337/rigv52.jpg[/img]
I’ve been terribly busy with something big, but today I found some time to work on my design again.
I changed it to 6 cards instead of 7. One powersupply (looking at a platinum rated 1500W now) should do fine. The boxes where the cards are in are now more detailed and two of them are perfectly sized for one 140mm fan.
[img]http://imageshack.us/a/img545/7599/rigv53.jpg[/img]
With the three fans at the back, behind the honeycomb grill, this should create some very nice heat removal. I put them on the inside now for protection of fingers and cables. Google some high speed fans and you will see as many pictures of injured fingers or someone shredding carrots on them as you see the actual fans. Also gives it a nice look. There is less material in front of the fan than standard grills (about 25%) with this design, so now it’s secure while still having a high airflow.
[img]http://imageshack.us/a/img16/4505/rigv55.jpg[/img]
The mainboard tray is simpler. Less struts. The power supply still can lean on the supporting strut below it though. The PCIE power cable for the last card might not be long enough, but an extension for that is cheap.
As an added feature, it can be stacked and even secured sideways to the same model of rig. I will make more than one for certain.
Laying out the pieces now so I can send it off to be lasercut. The struts I will cut myself.
I ordered up an MSI Z77-GD65 board upon multiple recommendations, which will replace my GD45 board. Mainly because it seems to be able to handle 6 cards with less problems then the GD45. Also ordered up an [url=http://www.enermax.com/home.php?fn=eng/product_a1_1_1&lv0=1&lv1=52&no=191]Enermax 1500W[/url] powersupply which is rated 80 platinum.
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I’m glad your still working on this. ;)
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Still plugging away at it.
I though about adding some flourishes, but I think I’m fine with how it is now.
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just a heads up. my enermax maxrevo 1500w psu could not handle 5x7950 +1x7970 card…
no problem with 5x7950. but that extra card put it over the top.
not platinum rated tough -
:o
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[quote name=“svennand” post=“13211” timestamp=“1370986673”]
just a heads up. my enermax maxrevo 1500w psu could not handle 5x7950 +1x7970 card…
no problem with 5x7950. but that extra card put it over the top.
not platinum rated tough
[/quote]
Thanks for the heads up. I think that exactly those two things are pushing it over the limit, the non platinum rating and the 7970. From my calculation, it should be enough, but I’ll know for certain once I have it running. -
[quote name=“ChristianRiesen” post=“13526” timestamp=“1371022942”]
[quote author=svennand link=topic=387.msg13211#msg13211 date=1370986673]
just a heads up. my enermax maxrevo 1500w psu could not handle 5x7950 +1x7970 card…
no problem with 5x7950. but that extra card put it over the top.
not platinum rated tough
[/quote]
Thanks for the heads up. I think that exactly those two things are pushing it over the limit, the non platinum rating and the 7970. From my calculation, it should be enough, but I’ll know for certain once I have it running.
[/quote]seems that the amount of power of the psu wasnt the problem…
however it does seem that active connectors might be a good idea with 6+ cards…
http://forum.feathercoin.com/index.php?topic=1609.15