Project: Stealth Mining Rig

[nookiegirl]

I want to set up a closed-case btc mining rig that looks like an ordinary computer.
Is it even possible such a thing would survice with 4 GPU cards going crazy inside?

I know it is not that easy from what I read so far, but it should be possible, right?

My Plan so far is to separate the graphics card.
One should normally go into the pci slot and the other 3 will be connected via risers and placed at different locations inside the case.


What is your feeling about it? Do I need a water cooling system for that or will air be enough when there are many?

[ryepdx]

Probably water cooling. For reference, I have 3 6990s on an open-air rig sitting directly below a large AC unit and it takes two Ultra Kaze fans blowing directly on the chips to keep them at 80 degrees Celsius. I don't think 4 cards would last very long in an enclosed case, personally, but they might do alright if you spread them out, give each one its own fan, and somehow turn the whole case into a veritable jet-intake without giving up that "regular computer" look.

Thing is, you probably won't be able to spread them out that much. PCI risers only give you about 6 inches, which sounds like a lot but really, in practice, isn't so much. Especially since you have to keep slack in them to keep from pulling them out of their slots, and since you can't twist them more than maybe 30 degrees at most without losing significant length.

P.S.
If your cards are anything like my 6990s, even if you manage to make the case look *normal* while incorporating awesome ventilation, the sound's going to give it away. And the heat. "Hey, why does your computer sound and feel like a hair dryer? You wouldn't happen to be mining, would you?"

Yeah. For stealth, water cooling all the way.

[nookiegirl]

"Hey, why does your computer sound and feel like a hair dryer? You wouldn't happen to be mining, would you?"

That just made my day :-)

Yeah, the bad news, it's going to be 4x 7970.
The good news, sound is not a problem as the pc would be in another room (not air conditioned).

Are there any recommendations on the case for a closed one?

[Singlebyte]

No water needed....just buy these:

https://bitcointalk.org/index.php?topic=195004.0o

Totally stealth....

[mt_bird]

"Hey, why does your computer sound and feel like a hair dryer? You wouldn't happen to be mining, would you?"

That just made my day :-)

Yeah, the bad news, it's going to be 4x 7970.
The good news, sound is not a problem as the pc would be in another room (not air conditioned).

Are there any recommendations on the case for a closed one?

I'm using a Cooler Master HAF X case with 3x 7950 with good results. I think you might be able to fit 4x 7970 in there with creative use of risers. You would want to remove the dust covers from the various grills to improve airflow.

[dogie]

I would say don't attempt this. Removing 800W of heat is hard enough, to get it quiet on air almost impossible.

[nookiegirl]

...to get it quiet on air almost impossible.

It does not have to be quiet. It can be loud as hell. I just need it to have a stable cool temp in the closed case.

[massnerder]

I am in the same boat, have had trouble finding a case with 12 or more slots in the back to space out the cards.  And if I did, some of the slots still wouldn't be able to hold a card with the mobo / risers getting in the way of where it would need to sit to fit into the backpane.  If you do get it set up right I would love to see it, or at least know which case you used to make it happen!  I am just using the crate rig method right now but would limit it to 2 or 3 cards if I needed it to hide in a regular case.

[Gomeler]

Go with full-card waterblocks. You can easily dump the ~0.8-1 kW of heat coming out of 4x 7970s with fullcover blocks and sufficient radiator to support it. Chances are you won't be able to mount the radiator within the case though.

[Bitweasil]

If you try, you can cool 4 cards on air fully contained in a case.

http://blog.cryptohaze.com/2012/02/quad-gpu-builds-with-case-part-2.html

That said, I don't recommend it, and have since moved to 3 cards per system with 1 space between them for better cooling.  This is easier to power, easier to cool, and keeps cards significantly cooler.  This is the "standard build" now for the boxes I've got in a data center.

[nookiegirl]

So as far as my theory goes, I made up this (unprofessional) little sketch.





What do you think? Could it stand 4 cards this way?
Any better spread of the fans?

[crazyates]

Those HAF X cards let you put a full 360mm RAD in the top, and keep it inside the case. Maybe go the WC route and do that?

[computerparts]

No. Not unless you want to turn your case into an easy bake oven. 3 cards max. Each spaced evenly. Case must have good airflow and wire management. Your sketch is a perfect example of what not to do. The cards are not spaced at all and won't receive any fresh air due to:

1. being sandwiched together.
2. cable obstruction.

[computerparts]

Those HAF X cards let you put a full 360mm RAD in the top, and keep it inside the case. Maybe go the WC route and do that?

360mm rad isn't enough for 4 cards. You would need 480mm minimum and a damn good one at that. And water cooling gets expensive real quick.

[phillipsjk]

I think I would have the side fans pull in fresh air (pressurizing the case, making the GPU fans do less work).

If you can wait, I would consider using ASIC for a stealth mining rig. A mini ITX board should leave lots of room for 4 of klondike 64 boards. I have not investigated how much case modificatuion would be required to mount them though.

https://bitcointalk.org/index.php?topic=190731.0

200W should be more stealthy than 800W

[Bitweasil]

No. Not unless you want to turn your case into an easy bake oven. 3 cards max. Each spaced evenly. Case must have good airflow and wire management. Your sketch is a perfect example of what not to do. The cards are not spaced at all and won't receive any fresh air due to:

1. being sandwiched together.
2. cable obstruction.

Actually, that case did work just fine to keep those cards cool.  It wasn't great, which is why I eventually moved to 3 card designs, but the biggest issues is that while nVidia cards have a nice step at the intake to deal with being crammed together, AMD cards don't, so don't cool nearly as well in that configuration.

The case door fans draw air IN - the cards suck air from that area, so blowing cool air into them helps a lot.

It works, but I don't use 4 cards in that configuration anymore for good reasons.

[computerparts]

No. Not unless you want to turn your case into an easy bake oven. 3 cards max. Each spaced evenly. Case must have good airflow and wire management. Your sketch is a perfect example of what not to do. The cards are not spaced at all and won't receive any fresh air due to:

1. being sandwiched together.
2. cable obstruction.

Actually, that case did work just fine to keep those cards cool.  It wasn't great, which is why I eventually moved to 3 card designs, but the biggest issues is that while nVidia cards have a nice step at the intake to deal with being crammed together, AMD cards don't, so don't cool nearly as well in that configuration.

The case door fans draw air IN - the cards suck air from that area, so blowing cool air into them helps a lot.

It works, but I don't use 4 cards in that configuration anymore for good reasons.

I find it very difficult to believe those cards were not suffocating. Nvidia or not, any card sandwiched together like that takes in heat from the card directly below it. I can't see how those cards were getting any fresh intake at all.

[Bitweasil]

The case door fans push a lot of air into the card intake, and the front fans push a lot of air into the case.



I totally agree with you that it looks like it shouldn't work, but it does work just fine.  YMMV, and as noted, I wouldn't do it with AMD cards, but I've known people who packed 4 6990s into the same case and kept them perfectly cool while running.

[philips]

Aside from hardware tricks you should go undervolting your cards.
It will reduce temperatures dramatically.

(Depending on energy and BTC price, it will increase profit too.)

[DBG]

It will be a challenge, but affording the cards themselves it the biggest challenge which you seem to have met.  I don't particularly like that case, I would really recommend something from the "Lian-Li Lancool" line or even better, a Antec Twelve Hundred V3 would be perfect.  A friend of mine used 3 of these cases to run a series of computers that was used as a homemade HPC lab (the 4 AMD GPUs were running full on 24/7).  It was housed in a closet, but even with the door open it was relatively quiet.  Water cooling would have been a requirement except a square was cut out of the side window, in which a block of aluminum was milled specifically for the setup and a 200mm fan drew away heat up and out of the closet.

I know there are people on this board that have access to such milling machines, but if you are in a location where there are designers or a college/school of design, they will likely be happy to help with your project (or maybe the people that live around me are just kind of hippyish in that way =p).  Other metals can be used of course, however the aluminum was a no-cost option for us as it was being used as a doorstop/scrap from a larger project.  Good luck!