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Assuming I had free power for a few months but must keep my rig in a semi restricted area and keep it semi quite what would you recommend doing? The best I could think of was getting a full tower HAF-932 and trying to get 6 5830s going. Semi warm area as airflow via fan can not be provided.

My boss is interested in bitcoin and is 100% willing to donate a few months of power assuming it is not disruptive due to sound. It also has to work in an enclosed space so it can not get to hot. This also will not be running 24/7 so I have to keep hardware costs in mind. I am open to ideas. Thanks.

1) Keeping hardware costs in mind, maybe a HAF-932 is overkill ;)

2) 5830s are noisy and hot.  6 of them will warm up any room, and will not handle an enclosed space well.  If you can't vent in cool air / vent out hot air, 6 of just about any cards are too many.

3) Look at eg. 5770/6770 instead - they're relatively low power (100W?) and produce a decent hashrate (~180-200MH/s), pretty close to a 2 MH/w ratio.  This doesn't matter as much since your power will be free, but lower power usage = less heat, so efficiency is a real concern here too.


To give some perspective, I ran 4x 5830 and 4x6950 in my basement in a well ventilated room, pulling *cold* air in from outside - even when the outside temps were 35-40F, they heated my entire house, to the point I often had to open more windows.

[edit] Additionally, make sure your boss understands exactly how much power is in question here - a rig with 6x 5830 is going to draw about 1-1.2KW at the wall.  Sapping free power for bitcoins probably isn't worth your job ;)

Considering what your boss may be willing to lay down for power costs, perhaps you might want to look at FPGA solutions instead - low heat, low power, but higher upfront costs. 

A 'few months' of powering ~180W 5830s could easily pay for a couple of the available solutions floating around the boards that only pull ~10W.

This is kind of a prime example for the argument that 'free power is never free - someone pays for it', since you actually interact with that someone it may be worthwhile to, you know, not suck them dry.

Power = heat.

Whatever power you rig uses it will be converted into heat.
So 1kW rig (at the wall) is going to produce 1kW of thermal output.

Having free electricity but a limit on heat is no different than a limit on electricity.

Not with an air conditioner plugged in it isn't.

A lot of companies get power at a fixed rate with no consideration of usage. That's why there office lights are on 24/7.

I really have no idea how these would perform, but I know that SIX 5830's would be disruptive to a quiet office environment.

Rather than lugging around the full tower, these laptops have the AMD 6990M , which would probably due for mining.  In addition, the Sager can handle dual 6990Ms.  

Should you take this route let us know what kind of numbers you get mining.  

Theoretically, you can just plug your laptop in whereever you see an outlet, just keep an eye on it, or it will be gone in a flash.

http://www.sagernotebook.com/index.php?page=product_info&model_name=NP7282

http://www.ibuypower.com/Store/Battalion_101_P150HM_Gaming_Laptop

a laptop like that is going to be just as bad for noise as a high powered desktop, he wants to go with a custom setup regardless of card with watercooling and one or more large radiators with low rpm fans. (small car radiator or heater core even)

Someone should build an "electric heater" that is really just a mining rig in a box with a wireless connection and give it away for free to the elderly and poor. It will work just as efficiently as any other electric heater.

I just can't imagine lugging a full tower around.

I'm not sure the 6990M has the same requirement as the standard 6990.  I'm sure it won't have the same power draw. I also can't imagine a laptop that's as loud as a full tower.

Fogetting about all the power and noise, is now the right time to be expanding your bitcoin hardware?

I mean what is the payback time for ANY hardware purchased for mining?

6990M has 1120 stream processors - you're going to see performance roughly equal to, possibly significantly less than a 5830/6870.

You're also going to constantly hit thermal ceiling trying to mine with a laptop.

Basically you'll be paying upward of $1500-2000 for a laptop that doesn't perform as well as a card you can get for $80 on eBay. 

As for noise, the rather tiny fan spinning at a relatively high RPM will tend to whine like a banshee.  It may be 'quieter' than the desktop card, but it'll probably be a far more annoying noise.

Yeah, I just saw a review.  The 6990M has 100W TDP.  I would have hoped for better in a laptop.

Water cooling won't reduce the thermal load.  Water cooling makes the heat transfer more efficient reducing noise and required airflow but energy in = energy out.

If the rig draws 1000W at the wall it will dump 1000W into air.

Why does it need to be in air? My dryer produces 800W of heat, but it all goes outside. It could just as easily be fanned underground as well.

Well given this is an office building I doubt he can drill a hole into the ground or cut a hole in the walls.  The rig will be in his office/cubicle so it will be dumping any energy drawn from the outlet right into the immediate area. 

My point was the OP should consider this a space heater.  Does he want a x watt space heater going 24/7/365 right next to him.  Watercooling can make it more efficient and quieter but it can't reduce the amount of wattage it throws off.

Well this whole ordeal doesn't seem like a good idea for you. I think you'd be better off sending me money.

http://s6.postimage.org/9til55g99/Mining_Rig_Free_Elec.jpg (http://postimage.org/image/9til55g99/)

You can't, and if you could, you would still lose money.

Change the numbers to you liking here
http://tpbitcalc.appspot.com/ (http://tpbitcalc.appspot.com/)

Until the hardware is paid off.. the break-even in your image is 96 days, after that's it's pure profit.

But $400 is going to get you more like 600mh/s.

A pair of 5970s would get you to about 1.4-1.5gh/s, but they're on average $400 each.

I'd budget maybe $250 for the mobo, ram, cpu, and PSU.  You're looking at more like $1050 for the system..

Long and short is even with free power it'll be a while before you've paid off the hardware at current difficulty & price, but depending on how long you want to leave it running you could eventually make a profit.

From the OP

Indeed, but the OP never stipulated anything other than 'a few months', is that more than 3 months?  Fewer than 9?

Just throwing figures out like everyone else ;)  

OP needs to actually do the math to see whether or not it's worthwhile, we can bark at the fence all we want otherwise.

Let us know how it goes.

Just run only  two (if needed, underclocked  and undervolted) cards per case during the day, and run them all full blast past office hours.
its not hard to have a few cards run virtually silent if you compromise on density. Both of my machines are whisper quiet and my GPUs are all well below 60C. All you need is something like twin frozr cards or good after market coolers in a case thats reasonably well ventilated with lots of silent fans. With only 2 or so cards per rig, thats easy. Any half decent gaming case will do (I have an antec 300, its dirt cheap and plenty good for 2 cards).  Its not very power efficient, but you wouldnt care.

Water in cooling loop won't ever get more than 50C or so.  The larger the radiator the lower speed fans you can use to acheive same temp.  So can't say how silent until you decide what cards (how much thermal load), and what size radiator. 

I run 3x5970 and i5-2500K at <45C and using 4x120mm it is essentially inaudible.

I have 2 rigs running in my office. The specs are as follows:

Rig 1: 4x 5850
Rig 2: 2x 5870, 1x 5850
I have 1 desktop fan blowing on both.

I have 1x extenders and cable ties (zip ties) to space out the cards, it depends on your case.

The 2 5870 have aftermarket HSF on them.

They are quiet, but there's heat and you cannot put it under your desk if you want kids in the future (might be as bad as putting a hot laptop on your lap).  ps. I'm not a doctor, but it's up to you.

So how to keep them quiet?
Set them up and don't start mining yet. Try out different levels of the fans on the GPU and once you have decided on a noise level you can accept (I have the sapphire non-ref at 65%, ref at 35%), lock in the fans at that speed. To do that I use cgminer as the mining software with the "--auto-fan --gpu-fan 65" parameter.

I've also setup cgminer with "--auto-gpu" to set the gpu to be down clocked if the temps get too high. I set the range to 500-880mhz. The reference card I have will run at a lower speed, but everything is stable.

I do not keep the air-conditioning on over-night. This will drive up the power bills significantly, so at night, the gpus automatically downclock to about 600mhz. During office hours when the air-conditioning is on, cgminer push them back to 750-880mhz (different for each card, as the card at the end runs cooler).

This is how they look:

http://www.btc-poolwatch.com/public/images/2rigs.jpg

Hope this helps.

Just saw your TyGrr setup photos. I think you should be able to do this easily.

I understand the flood in Thailand is subsiding. Hope it did not affect you much.