Optimal Bitcoin Mining Corp. now offering remote GPU use contracts!

[optimalbitcoinminingcorp]

https://i.imgur.com/UK0Bt.png

Hi I'm optimalbitcoinminingcorp - you might recognize me as dubious on IRC around the bitcoin channels. Teaming up with me is AnonX, who is a recognizable user on the bitcoin-IRC channels. Additionally, I have been speaking with Nefario over IRC to prepare this IPO for launch. (he can verify this as well)  I'm very excited to announce Optimal Bitcoin Mining Corp. a new bitcoin mining business, which is the first bond offering and largest IPO on GLBSE.com to date.

Currently, I am running 15 gpus at around 4 Ghash/s, so I've invested about $5.5k of personal funds and I am looking for bonds as loans to expand my cluster to around 40 Ghash/s.   I would like to raise $45k for expansion funds within the next month.

We are issuing 0.8 btc bonds that mature at 1 btc on or before December 1, 2011.

The way this venture differs from those that exist so far is that as far as I know, this is the first bitcoin mining company in which 10% of the total profits will be donated to a few different charities including at least one aiming to benefit the Bitcoin community. The specific charities have not yet been determined and I will allow the investors to make suggestions causes they would like to see benefit. The idea is that with the recent negative publicity surrounding Bitcoin in the US news, it's important for our image to be redefined in a more positive light.  I see great potential in Bitcoin for the future and I don't want to see U.S. government regulation ruin this for everybody.  Additionally, this should encourage a "feel good" mentality that comes from giving to others that should benefit the bitcoin community and cause it to grow in countless ways, while increasing chances of survival.
Here are our numbers:

Each computer will be built primarily with mining in mind, but also with some consideration towards retaining high resale value.  Each computer will contain approximately 5x hd 5830, 3.1 ghz Athlon ii x4 processor, 4 gb ram, 16 gb sd card, 3 coolermaster sickleflow 120 mm fans for case airflow, dvd-rw drive, thermaltake v3 black edition case, 1200 W power supply, motherboard that has slots for 5 graphics cards, 3 pci-e extender cables
The space used will be a commercial space 350 sqft., approximately 10-15 minutes driving distance from dubious, who will be taking care of installing and maintaining the equipment and costs $350/month to rent.  At approximately 20 computers there will be an upgrade cost of about $4,000 to upgrade the electricial system to support the additional load.

Here is a picture of the 350 sqft space:
http://img832.imageshack.us/img832/7467/350sqftspace.th.png

The ceilings are 7.5 feet high, but this will be sufficient as the server racks are 6 feet high.  We will be using this space to begin with and if it turns out we need more space, there is a 250 sqft space next door that is vacant.  The debris on the floor and all dust will be vacuumed out before we move in.
To prevent the systems from overheating, there is air conditioning in the building that will be turned up full blast, plus we will be building a ducting system that directs heatflow out the window.  If needed, a portable air conditioner or window air conditioner can be purchased cheaply to cool a space this size.
The cpus will not be overclocked, but the core clock of the gpus will be increased to the highest tested stable frequency, and the memory clocks will be underclocked as much as possible to reduce power consumption.

Each computer will cost approximately $900.  Only one monitor will be purchased for the whole system along with kvm switches daisied together to reduce total expenses.

We have compiled several Excel spreadsheets that I put into Google docs for investors to view.  We expect difficulty to continue rising at around 50% per two weeks.  At this rate and approximating the value per bitcoin to be $20, bitcoin mining will remain profitable for 2-2.5 months.  In this amount of time, we expect to make $14858.49.  However, there are several different cases: if the bitcoin value goes to $50 we make $70,000 over this time period. ($30->$33,238.93 and $40->$51,619.38)  In the case where the bitcoin drops to $10 we run a loss on our hardware of -$1,845.44.  In case the bitcoin does not retain value, we have a plan B.

Here are our numbers:
https://spreadsheets3.google.com/spreadsheet/pub?hl=en_US&hl=en_US&key=0AmTXg8oCxjy5dDRYa3NPNDVlMnBSR2E2LV9VOHZWRlE&output=html

You can buy the bonds by creating a new web account for the web client for GLBSE.com here: http://dev.glbse.com:4567/client/index.html
Then generate a key pair and register, deposit some bitcoins and you are ready to go.
The asset ID is cbc7c9f999f94665e599d0ab0e144e1953e40d399a0f9191b91b843db4bb92da
The Ticker Symbol is OPTIMALBITCOIN

If you have any questions about getting started, concerns or feedback you can post them on this thread or email us at optimalbitcoinmining@gmail.com.

Thank you for taking the time to read this and stay tuned for further updates!

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[cunicula]

How much US$ per KwH in your location? In the long-run, this will be a deciding factor on who is driven out of the business.

[optimalbitcoinminingcorp]

Cost per kWh is $0.16 at this location.  We determined that at $20/btc, we will be able to mine profitably until the difficulty reaches 4800000.  Once the difficulty reaches this level, if the value of the bitcoin is not higher than $20, we will switch to our plan B, which we are not ready to make public yet, but I will say that plan B is not dependent on the bitcoin at all and is more profitable than bitcoin mining.

[cunicula]

Why not just solicit shares for plan B if it is more profitable?

[Capitan]

I can't tell if your post is a joke, or a scam or if you simply haven't thought it through.

How can the computers you described only cost $900? Even if you had all the other parts and only needed to buy the 160 5830's needed to reach 40GH/s, you'd spend about $180 per GPU. One hundred sixty Radeon 5830's at $180 a piece. I suppose that's about the going rate for that card right now, if you could even find them for sale. Now you need to assemble all the other parts for 32 systems: Athlon II X4's, 4gb ram, DVD drive (pointless for mining), cases, motherboards, 1200W power supplies, fans, and PCIe riser cables. The case you linked to won't hold 5 GPU's without mods. Add $ for that, even if it's just shelves to prop up the cards.

Parts:
mobo   $130.00
PCIe extenders   $30.00
ram   $25.00
PSU   $180.00
case   $40.00
hdd   $20.00
DVD   $20.00
cpu   $80.00
Fans   $20.00
Total: $545 without video cards
Total with video cards @$160 each: $1345
x40 = $43,040.00  just for the machines alone.

Good luck getting all those parts and the video cards, for that price in under a month. The price of a bitcoin has already fallen from $20 to $15 and it's only been a day since you made this thread. Counting on the price to stay steady is crazy with something as a volatile as bitcoins. The difficulty will adjust more than every 14 days. More like every 8-10 days. At that rate the difficulty will have already increased AT LEAST 3 more times between now and when you finally get up and running (this assumes you are able to raise money and get your operation up and running at an above average speed). So by the first week that you are up and mining, electricity will already be 87% of your revenue (assuming bitcoins are still $15 at that time, which could go either way). After your 10th day of mining electricity jumps to %135 of your revenue. From then on out who knows what happens. People will begin to drop out of mining so you drop out so you might put your operations on pause or just keep mining with the expectation that you might lose money for a while while you wait for people to drop out.

Also consider that 40x of these rigs, is going to put out about 29,000W of heat. I'm basing that of actual measured power draw from my own system with 2 5830's, extrapolated to 5 cards. That's 115W/sqf, which is in datacenter territory. You should research what spec of AC you actually need to cool off this kind of heat. And be careful to not use more than 80% of the max amperage for each electrical circuit.

Good luck finding investors who will invest in a plan where the #'s already exceed your planned costs, and that will begin to lose money after about 10 days of getting the operation up and running, and only get worse from there, or stay near a barely break even point. Then how are you going to deal with liquidating your "company" when you go under? I'm assuming you're going to either start an internet gaming center or sell the PC's.

If your plan B were more profitable than mining why would you not just jump straight to plan B? I'm guessing it's because you expect a bunch of strangers online to pay for your hardware so you can actually do "Plan B". But if Plan B is as well thought out as Plan A, you should assume there will be a high probability of that plan failing within the first 45 days. Would the cash from liquidating the hardware be split evenly among the bondholders? Or do you for some reason get the privilege of keeping the hardware and/or cash and leaving the suckers, i mean, investors, high and dry?

Note: i assumed 260Mh/s per 5830. I guess if you overclock you could get more than that, but you'd also be using more electricity and generating more heat so that would only at best buy you about another week of operating before you start losing money.

[Capitan]

Edit, my calc's were a smidge harsh, but still pretty much made sense

1x 5830's = 260Mh/s
40,000Mh/s / 260Mh/s/card = 154 cards
@5 GPU's system: 154 GPU's / 5 GPU/sys = 31 systems
31 * $1,345 = $41,695

+ deposit + rent + AC + fans + electrical installations + internet + racks + networking equipment + KVM's + surge protectors


If you are making a profit with your current total of 15 GPU's you should consider yourself really lucky and just mine those until it's no longer profitable. Then put all your money into Plan B.

[cunicula]

That electricity will jump to 135% of revenue seems absurd to me.  How much of mining is conducted below ~$0.12 KwH with no other costs in terms of hardware depreciation? It would have to be a large fraction for a near-term movement like this where electricity cost > revenue at $0.16 per KwH. I think it will take about a year for mining to move to low cost locations, so they might have a timing window though I agree that it is dodgy.

People who set up ops in areas where electricity is heavily subsidized such as the Ukraine [$0.03 per KwH] have the best investment prospects.
http://en.wikipedia.org/wiki/Electricity_pricing

Note: I am not suggesting that anyone send coins to Ukrainian scammers who set themselves up on GLBSE. Just that if you live in the Ukraine, investing in mining is probably still a good idea.

[optimalbitcoinminingcorp]

I can't tell if your post is a joke, or a scam or if you simply haven't thought it through.

How can the computers you described only cost $900? Even if you had all the other parts and only needed to buy the 160 5830's needed to reach 40GH/s, you'd spend about $180 per GPU. One hundred sixty Radeon 5830's at $180 a piece. I suppose that's about the going rate for that card right now, if you could even find them for sale. Now you need to assemble all the other parts for 32 systems: Athlon II X4's, 4gb ram, DVD drive (pointless for mining), cases, motherboards, 1200W power supplies, fans, and PCIe riser cables. The case you linked to won't hold 5 GPU's without mods. Add $ for that, even if it's just shelves to prop up the cards.

Parts:
mobo   $130.00
PCIe extenders   $30.00
ram   $25.00
PSU   $180.00
case   $40.00
hdd   $20.00
DVD   $20.00
cpu   $80.00
Fans   $20.00
Total: $545 without video cards
Total with video cards @$160 each: $1345
x40 = $43,040.00  just for the machines alone.

Good luck getting all those parts and the video cards, for that price in under a month. The price of a bitcoin has already fallen from $20 to $15 and it's only been a day since you made this thread. Counting on the price to stay steady is crazy with something as a volatile as bitcoins. The difficulty will adjust more than every 14 days. More like every 8-10 days. At that rate the difficulty will have already increased AT LEAST 3 more times between now and when you finally get up and running (this assumes you are able to raise money and get your operation up and running at an above average speed). So by the first week that you are up and mining, electricity will already be 87% of your revenue (assuming bitcoins are still $15 at that time, which could go either way). After your 10th day of mining electricity jumps to %135 of your revenue. From then on out who knows what happens. People will begin to drop out of mining so you drop out so you might put your operations on pause or just keep mining with the expectation that you might lose money for a while while you wait for people to drop out.

Also consider that 40x of these rigs, is going to put out about 29,000W of heat. I'm basing that of actual measured power draw from my own system with 2 5830's, extrapolated to 5 cards. That's 115W/sqf, which is in datacenter territory. You should research what spec of AC you actually need to cool off this kind of heat. And be careful to not use more than 80% of the max amperage for each electrical circuit.

Good luck finding investors who will invest in a plan where the #'s already exceed your planned costs, and that will begin to lose money after about 10 days of getting the operation up and running, and only get worse from there, or stay near a barely break even point. Then how are you going to deal with liquidating your "company" when you go under? I'm assuming you're going to either start an internet gaming center or sell the PC's.

If your plan B were more profitable than mining why would you not just jump straight to plan B? I'm guessing it's because you expect a bunch of strangers online to pay for your hardware so you can actually do "Plan B". But if Plan B is as well thought out as Plan A, you should assume there will be a high probability of that plan failing within the first 45 days. Would the cash from liquidating the hardware be split evenly among the bondholders? Or do you for some reason get the privilege of keeping the hardware and/or cash and leaving the suckers, i mean, investors, high and dry?

Note: i assumed 260Mh/s per 5830. I guess if you overclock you could get more than that, but you'd also be using more electricity and generating more heat so that would only at best buy you about another week of operating before you start losing money.

I will point out most of the costs you mentioned to add are minor.  Also, I am paying less than you have indicated for motherboard, case, extender cables, and I am going with a 1 kW PSU instead of the 1200 W, which also decreases electricity requirements per computer by 17%, which will make a big difference.  This reduces the electricity cost over 11 weeks by $2,365.44.  This allows an increase in cost per computer of 2365.44/40*4=$236.54, since there are 40 computers and 3/4 of the initial cost is recovered from salvage value.  The cost of graphics cards did increase since my original calculation, so $1000-1100 is a more realistic figure for cost per machine, which still indicates a greater profit when compared to my original calculation with a 1 kW PSU.  With regard to cooling, I plan on building a ducting system with large fans that direct heat out the window.  Additionally, I will be installing a 12000, 18000, or 24000 BTU window A/C unit for $250-$450 to cool a 350 sqft space.  Plus, there is A/C already in the building.

[Capitan]

I can't tell if your post is a joke, or a scam or if you simply haven't thought it through.

How can the computers you described only cost $900? Even if you had all the other parts and only needed to buy the 160 5830's needed to reach 40GH/s, you'd spend about $180 per GPU. One hundred sixty Radeon 5830's at $180 a piece. I suppose that's about the going rate for that card right now, if you could even find them for sale. Now you need to assemble all the other parts for 32 systems: Athlon II X4's, 4gb ram, DVD drive (pointless for mining), cases, motherboards, 1200W power supplies, fans, and PCIe riser cables. The case you linked to won't hold 5 GPU's without mods. Add $ for that, even if it's just shelves to prop up the cards.

Parts:
mobo   $130.00
PCIe extenders   $30.00
ram   $25.00
PSU   $180.00
case   $40.00
hdd   $20.00
DVD   $20.00
cpu   $80.00
Fans   $20.00
Total: $545 without video cards
Total with video cards @$160 each: $1345
x40 = $43,040.00  just for the machines alone.

Good luck getting all those parts and the video cards, for that price in under a month. The price of a bitcoin has already fallen from $20 to $15 and it's only been a day since you made this thread. Counting on the price to stay steady is crazy with something as a volatile as bitcoins. The difficulty will adjust more than every 14 days. More like every 8-10 days. At that rate the difficulty will have already increased AT LEAST 3 more times between now and when you finally get up and running (this assumes you are able to raise money and get your operation up and running at an above average speed). So by the first week that you are up and mining, electricity will already be 87% of your revenue (assuming bitcoins are still $15 at that time, which could go either way). After your 10th day of mining electricity jumps to %135 of your revenue. From then on out who knows what happens. People will begin to drop out of mining so you drop out so you might put your operations on pause or just keep mining with the expectation that you might lose money for a while while you wait for people to drop out.

Also consider that 40x of these rigs, is going to put out about 29,000W of heat. I'm basing that of actual measured power draw from my own system with 2 5830's, extrapolated to 5 cards. That's 115W/sqf, which is in datacenter territory. You should research what spec of AC you actually need to cool off this kind of heat. And be careful to not use more than 80% of the max amperage for each electrical circuit.

Good luck finding investors who will invest in a plan where the #'s already exceed your planned costs, and that will begin to lose money after about 10 days of getting the operation up and running, and only get worse from there, or stay near a barely break even point. Then how are you going to deal with liquidating your "company" when you go under? I'm assuming you're going to either start an internet gaming center or sell the PC's.

If your plan B were more profitable than mining why would you not just jump straight to plan B? I'm guessing it's because you expect a bunch of strangers online to pay for your hardware so you can actually do "Plan B". But if Plan B is as well thought out as Plan A, you should assume there will be a high probability of that plan failing within the first 45 days. Would the cash from liquidating the hardware be split evenly among the bondholders? Or do you for some reason get the privilege of keeping the hardware and/or cash and leaving the suckers, i mean, investors, high and dry?

Note: i assumed 260Mh/s per 5830. I guess if you overclock you could get more than that, but you'd also be using more electricity and generating more heat so that would only at best buy you about another week of operating before you start losing money.

I will point out most of the costs you mentioned to add are minor.  Also, I am paying less than you have indicated for motherboard, case, extender cables, and I am going with a 1 kW PSU instead of the 1200 W, which also decreases electricity requirements per computer by 17%, which will make a big difference.  This reduces the electricity cost over 11 weeks by $2,365.44.  This allows an increase in cost per computer of 2365.44/40*4=$236.54, since there are 40 computers and 3/4 of the initial cost is recovered from salvage value.  The cost of graphics cards did increase since my original calculation, so $1000-1100 is a more realistic figure for cost per machine, which still indicates a greater profit when compared to my original calculation with a 1 kW PSU.  With regard to cooling, I plan on building a ducting system with large fans that direct heat out the window.  Additionally, I will be installing a 12000, 18000, or 24000 BTU window A/C unit for $250-$450 to cool a 350 sqft space.  Plus, there is A/C already in the building.

What calculation did you use to come up with 17%? I'm guessing you used the following logic: "A 1000W PSU uses 200W less than a 1200W. 200W is 16.7% of 1200W, so we will use 17% less electricity." That's not how it works. I will let you do your own research about that and figure out why 17% is wrong. If anything you will use very slightly more power by dropping to a 1000W PSU.

Dropping to 1000W might be better in the long run because it would help you recoup costs faster, but it will definitely NOT help you on your electricity bills. My calculation for the PSU was practically a best case scenario for your power use, and I also did you a favor of using real power usage #'s I took from similar hardware. 29kW of electricity use and heat output is what you are going to be dealing with. I don't know how many BTU's you need to cool that. Please do your research on what kind of airflow and BTU ratings you need to cool such a setup for the given size before you try that out.

Why would you buy DVD drives to mine? If you need them for plan B, why not wait until you get to plan B before buying them. Is it because you know that the mining has no chance to begin with?

You will be chasing diminishing profits, and the major thing you overlooked is that by the time your systems are up and running the difficulty will already have increased 3-4 times. I based my previous figures on an estimate of 30% increases every ~10 days. 3 increases by the time OP first starts to mine, a month from now. The first increase after he starts will have him losing money (assuming a $15 BTC). I'm not saying that will happen, but that's a very realistic scenario. The BTC value could go up and make your venture worthwhile, but it could go down just as easily. The difficulty will certainly continue to rise, maybe a little slower, maybe a little faster. If an investor believed he/she were going to make money by investing in you they would essentially be banking on a rise of the BTC's value. If that's the case, they may as well put their money into the BTC RIGHT NOW, and get a 1 month head start on the scenario of investing in you (due to the lag it would take for you to collect investments and get everything up and running).

There is just so much that's not thought out. You still assume that you will be able to find the 5830's in the quantities you need, that you'll be able to put 5 GPU's into each system (where the case you linked to doesn't have the slots for this, you'd have to get creative), and that they would run cool enough. You claim to be able to get better prices on some of the components than what newegg is selling them for. Is there really a 5 PCIe slot mobo that has the correct slot spacing that would allow you to only require 3 riser cables per system, and that costs less than $130, that you can acquire 32 - 40 of? Are you sure about all of that. I'm not saying it's not possible, but from the looking around that I did when seeing if building new mining rigs would be worthwhile I didn't find anything cheaper that would allow the 5xGPU that you are aiming for. I'm sure it's out there though if one looks hard enough. 

I'll reiterate that the plan you propose is pretty risky for investors and no one with any sense would invest significantly in this scheme given your highly optimistic calculations; incorrect assumptions about power use = incorrect assumptions where else, risk of difficulty increasing to the point that you never turn a profit (and start losing money daily after 10 - 15 days due to electricity being more expensive than BTC earned), and risk of the BTC being worthless against the dollar in the future.

[Capitan]

Also, in my city the actual electricity bill ends up being about 2x higher than the $/kwh rate that is advertised. This is because you pay for taxes, flat fees, and then "delivery fees". My electricity supply is only $0.11/kwh, but my overall bill is more than double that.

Have you taken that into account? What the overall monthly electricity bill would be after all fees, surcharges, taxes, etc?

[cunicula]

Captain, extrapolating difficulty increases without accounting for profitability is stupid. There is no way that difficulty will continue to increase at 30% every 10 days unless the price goes back up to 30 or more. Notice how many people are selling used 5830s now in the forum. This is a strong indication that people are reluctant to add to capacity now and that difficulty growth will almost certainly slow. I think the real threat (and reason that I wouldn't invest) is that price could stagnate or fall somewhat, leaving people with big new investments in the lurch.

I wish someone would come up with a better use for GLBSE than mining. If someone trustworthy listed a somewhat professional sexcam or gambling site there, I would be eager to invest my coin. Bitcoin users almost all young men -> porn/gambling are perfect target markets.

[Capitan]

I agree, I simply stated that as a realistic scenario. Plus if difficulty slows it means the BTC's value is staying too low for it to be profitable for most people, which doesn't bode well for someone starting a $50K mining operation. The OP, or any potential investor, has to take both price and difficulty into consideration. And since those two factors sort of feedback on each other it is pretty hard to do. His original calculations were far too optimistic. Mine as well is not as pessimistic as some fairly realistic scenarios (difficulty continues uppping, but at a slower rate, while price steadily falls to or below $7 / BTC).

The only people who might have a good case for jumping in big now are those who live where electricity is < $0.08/kwh, and who can cool a big setup cheaply. Other guys will dump their hardware cheap once the BTC price no longer pays back electricity required to produce. The people with cheap power will buy that hardware cheap and produce bitcoins cheap. So that is also a potential scenario where difficulty would still continue to increase (I still think it would increase slower in this scenario as well. After the next jump I think the increases might be lower than 30%).

My guess is the difficulty WILL continue to rise until the electrical cost to produce BTC about meets the value of BTC in meatspace currency. Luckily the OP is on the cheaper side of things in terms of global electric costs (but still higher than the US average of $0.10/kwh).

And he still hasn't addressed the ownership in case the venture fails. Do investors get paid back through the sale of the hardware? And why would he still choose risky mining over Plan B if Plan B is more profitable?

[Capitan]

How would the online gambling work for US residents? Didn't they just do a huge crackdown on online gambling recently, and freeze a ton of accounts? Wouldn't using bitcoin for gambling just draw more negative attention?

[Capitan]

Bumping so we see both threads.

[optimalbitcoinminingcorp]

Okay, here is an update on the state of the company:

So far we have sold 15 bonds for a total of 12 BTC.  I expected more bonds to be sold, but I neglected threads and didn't really answer many questions, plus the last difficulty increase was huge.  This is still about $200 at current BTC value, which is 20% of the way to $1000 that is required to go forward with the project.  I have to acknowledge that the number of bonds sold to date indicates there is a lower demand for starting this business with plan A than I anticipated, therefore, I am moving to reveal plan B that will give investors a better idea of the direction the company is headed in.

Why not just solicit shares for plan B if it is more profitable?

Plan B is significantly more profitable than mining bitcoin.

So what is Plan B? 

Plan B is selling contracts upfront for distributed computing on a cluster that is used solely for General Purpose GPU computing and aims to be completely legal.  Every computer in this cluster will be built entirely by me as I have built quite a few computers recently and this is becoming rather easy for me and I enjoy it. 

While I will be building all of these computers myself and I have found a location that be ready for move in within a week or two, there are some logistics that will need some work.  I have a few people on my team already that I am working with in this project and I am looking one or two more that have prior experience with setting up servers, GPU farms, or remote networks, especially how to set up computers to serve as GPUs PM me for a brief interview.  Right now our first goal is to grow to 40 computers that can handle distributed GPU software.  If you are interested or I have already spoken to you about this please PM so I know you are still interested.  Employees will each receive 5% of the total profit generated.  I would like to limit the maximum number of employees at 5. (not counting myself)  I would try to do this myself, but instead I wouldn't mind sacrificing some of my share to get this thing running sooner and more smoothly.
 

How can the computers you described only cost $900? Even if you had all the other parts and only needed to buy the 160 5830's needed to reach 40GH/s, you'd spend about $180 per GPU. One hundred sixty Radeon 5830's at $180 a piece. I suppose that's about the going rate for that card right now, if you could even find them for sale. Now you need to assemble all the other parts for 32 systems: Athlon II X4's, 4gb ram, DVD drive (pointless for mining), cases, motherboards, 1200W power supplies, fans, and PCIe riser cables. The case you linked to won't hold 5 GPU's without mods. Add $ for that, even if it's just shelves to prop up the cards.
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.
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Also consider that 40x of these rigs, is going to put out about 29,000W of heat. I'm basing that of actual measured power draw from my own system with 2 5830's, extrapolated to 5 cards. That's 115W/sqf, which is in datacenter territory. You should research what spec of AC you actually need to cool off this kind of heat. And be careful to not use more than 80% of the max amperage for each electrical circuit.

I will point out most of the costs you mentioned to add are minor.  Also, I am paying less than you have indicated for motherboard, case, extender cables, and I am going with a 1 kW PSU instead of the 1200 W, which also decreases electricity requirements per computer by 17%, which will make a big difference.  This reduces the electricity cost over 11 weeks by $2,365.44.  This allows an increase in cost per computer of 2365.44/40*4=$236.54, since there are 40 computers and 3/4 of the initial cost is recovered from salvage value.  The cost of graphics cards did increase since my original calculation, so $1000-1100 is a more realistic figure for cost per machine, which still indicates a greater profit when compared to my original calculation with a 1 kW PSU.  With regard to cooling, I plan on building a ducting system with large fans that direct heat out the window.  Additionally, I will be installing a 12000, 18000, or 24000 BTU window A/C unit for $250-$450 to cool a 350 sqft space.  Plus, there is A/C already in the building.

What calculation did you use to come up with 17%? I'm guessing you used the following logic: "A 1000W PSU uses 200W less than a 1200W. 200W is 16.7% of 1200W, so we will use 17% less electricity." That's not how it works. I will let you do your own research about that and figure out why 17% is wrong. If anything you will use very slightly more power by dropping to a 1000W PSU.

Dropping to 1000W might be better in the long run because it would help you recoup costs faster, but it will definitely NOT help you on your electricity bills. My calculation for the PSU was practically a best case scenario for your power use, and I also did you a favor of using real power usage #'s I took from similar hardware. 29kW of electricity use and heat output is what you are going to be dealing with. I don't know how many BTU's you need to cool that. Please do your research on what kind of airflow and BTU ratings you need to cool such a setup for the given size before you try that out.

Why would you buy DVD drives to mine? If you need them for plan B, why not wait until you get to plan B before buying them. Is it because you know that the mining has no chance to begin with?

You will be chasing diminishing profits, and the major thing you overlooked is that by the time your systems are up and running the difficulty will already have increased 3-4 times. I based my previous figures on an estimate of 30% increases every ~10 days. 3 increases by the time OP first starts to mine, a month from now. The first increase after he starts will have him losing money (assuming a $15 BTC). I'm not saying that will happen, but that's a very realistic scenario. The BTC value could go up and make your venture worthwhile, but it could go down just as easily. The difficulty will certainly continue to rise, maybe a little slower, maybe a little faster. If an investor believed he/she were going to make money by investing in you they would essentially be banking on a rise of the BTC's value. If that's the case, they may as well put their money into the BTC RIGHT NOW, and get a 1 month head start on the scenario of investing in you (due to the lag it would take for you to collect investments and get everything up and running).

There is just so much that's not thought out. You still assume that you will be able to find the 5830's in the quantities you need, that you'll be able to put 5 GPU's into each system (where the case you linked to doesn't have the slots for this, you'd have to get creative), and that they would run cool enough. You claim to be able to get better prices on some of the components than what newegg is selling them for. Is there really a 5 PCIe slot mobo that has the correct slot spacing that would allow you to only require 3 riser cables per system, and that costs less than $130, that you can acquire 32 - 40 of? Are you sure about all of that. I'm not saying it's not possible, but from the looking around that I did when seeing if building new mining rigs would be worthwhile I didn't find anything cheaper that would allow the 5xGPU that you are aiming for. I'm sure it's out there though if one looks hard enough. 

I'll reiterate that the plan you propose is pretty risky for investors and no one with any sense would invest significantly in this scheme given your highly optimistic calculations; incorrect assumptions about power use = incorrect assumptions where else, risk of difficulty increasing to the point that you never turn a profit (and start losing money daily after 10 - 15 days due to electricity being more expensive than BTC earned), and risk of the BTC being worthless against the dollar in the future.

Capitan, you might be a troll in disguise, but you do make some didactic points so I will suspend belief for a moment and address your points

1.  My mistake, 4 GPUs per motherboard is more realistic to my build and this is what I am aiming for.
2.  The power requirements are dependent on the efficiency of the PSU so the power draw from the wall calculation becomes:

Phenom II x4 820 = 95 W
Athlon II x4 645 = 163 W
Radeon HD 5870 = 188 W
Radeon HD 5830 = 175 W
1200 W PSU = 82% efficient
1000 W PSU = 80% efficient

4x hd 5870 + athlon = 4*188 W + 163 W = 915 W so 1000 W would be sufficient for stock settings
209 W are available for each card so maximum overclock would be 850*209/188= ~940 MHz which is a decent overclock, but may not be stable so lets say 930 MHz as I've had more luck with this number

930/850*188*4+163= 986 W      /(80% efficiency) = 1232.5 W draw from wall - okay so 32.5 Watts off
and for the 82% efficient PSU you could choose this clock and use 1202.44 W - 2.44 Watts off for the 1200 W PSU
suppose you could get a 950 MHz clock using 1200 W PSU
thats 1223.74 W still within 3% error from the original calculation so this would increase electricity requirements by about 3% over initial estimates.  Not a huge difference in cost. 
3.  Cooling:  I will use the largest window air conditioner I can find, currently a $699 - 28500 BTU model.  I will also purchase three portable air conditioners of 12000 BTU for $300 each.  I will be using a datacenter style hot-cold aisle cooling two rows of server racks, one cold aisle in between the racks and a hot aisle between the rack and the wall.  I will be stacking 4 20" box fans by the window, 4 20" box fans half way in the cold aisle, and 4 20" box fans in each far corner from the window. (if you connect the placement of the box fans, they will form a "Y" shape).  I would place the portable AC unit opposite the window at the other end of the cold aisle.  Next I will be installing an aluminum hood above each server rack to capture rising hot air that will rise into the hood naturally via convection, so it can be fed up into the ventilation ducting and ejected out the window.  I will put a shutter and fans on the ducts that I can reverse when once the average outside temperature crosses below a certain temperature.  I will also install a 50W Air Purifier for $150.
4.  Profitability calculation for this project (here's the fun part)
$1.50/hr *24hr/day*7 days/wk*31 computers = $7,812 /week revenue
initial cost of computers = $50,000 at $1100*40=$44,000  leaves $6,000 for server racks fans and A/C
cost of electricity = $0.14 /kWh (this is commercial space so electricity is slightly cheaper than residential) * 1.224 kW/computer * 31 computers * 24 hr/day* 7 day/wk = $892.44/wk
+ Air conditioning current draw 4*16 = 64 Amps
(322 amps for computers)/10.2amps/computer = 31.5 computers
64 amps *120 V=7.68 kW * 24 hr/day*7 day/wk*$0.14/kWh=$180.63/wk
16 box fans draw 0.88*16= 14 A ->$39.51/wk
profit=$7812-$892.44-$180.63-$39.51=$6,699.42/wk or $348,000/yr
breakeven occurs in 50000/6962 = 7.46 weeks or less than 2 months

Also, I overestimated to leave some funds for extra expenses.

If I pay an employee 5% of profit that would be about $17,400 for a year.  Not too bad for a small consulting project!

Currently, I have 5 available computers that can be used to run any type of software remotely that performs GPU intensive calculations as long as you are not changing the clocks of the cards or doing anything else that might greatly increase the chance that the hardware might fail.  (this does not include running the GPUs at maximum capacity - they will be adequately cooled for this reason)   These computers will be used for initial testing and configuration and I would like to get them up and running ASAP.

If you know anyone who requires this service you can let me know how to contact them and you will receive 5% of any revenue that is generated by any of the leads that you pass to me.   
If you get a client for me that requires half this capacity, that would be $8,700 for you in 1 year.  Not bad for introducing me to a few friends!

Right now the hardware that I am running is all AMD, but I will build at least of the cluster to have nVidia hardware.  This service will be available as soon as we are able to get the software running properly, but I am working hard to get it started as soon as possible.  I estimate rates will be about $1.50/hour for use of a 3x HD 5830 GPU, but this is an estimate and, therefore, is subject to change at a later date, but for now, I will sell contracts at the rate of $1.50/hour.  Please let me know what kind of hardware you require when you make your inquiry.

Originally these rigs were intended to be a mining company, as I thought of this idea as a plan B, but I believe it has better prospects than the original, more certainty of its future and a better chance of being more profitable in the long run.

This company - Optimal Bitcoin Mining Corp. has bonds available on GLBSE.com (the ticker symbol is OPTIMALBITCOIN)  explanation of bonds: Each bond costs you 0.8 BTC and in return you receive 1.0 BTC on December 1st, 2011.  By buying bonds, you are essentially giving us a loan at a very favorable rate. (25% for 4 months or 75% annual)  The reason why this rate is so high is we need capital to build new rigs, and since we are a new startup, the rate must be high enough (some might say too high, but this is what I have set it at) to compensate for the risk involved. 

please PM me for further information or post to share your thoughts

[Ben Walsh (beamer)]

Can we get an update on this please ?

[optimalbitcoinminingcorp]

Latest update:

Currently the difficulty is increasing by 8.5% per 10 days.  I measured the power draw from each computer to get a more accurate idea of power requirements.  I found the power draw to be much lower than expected.    With these new calculations I can mine profitably after cost of electricity for another 4 months, until approximately November 26th.  The profit made until then at current rates cannot justify the cost of purchasing new hardware therefore I am renting out these computers for GPGPU computing, which are remotely accessible.  Also, instead of building a cluster for Bitcoin Mining, I am building a cluster for distributed GPGPU CUDA and OpenCL computing.  The costs and profits detailed above are correct, except the electricity draw for each 4x HD 5870 machine would be about 900 W.  This now allows 42 computers in this space with a 400 A service utilizing 80% of capacity.
$0.14*0.9*7*24*42=$889.06/week electricity cost
$1.5*7*24*42=$10,584/week revenue
10584-889.06-180.63-39.51=$9474.80/week profit
$492,689.60/year profit

I have found several people who I will be working with to set up the cluster and I am teaming up with NetTecture to provide additional capacity in case either of us receive a larger order than we can handle.  If you are interested in a buying a contract send me a PM and I will be happy to set it up for you right away. 

Bond offerings via GLBSE.com have not been very effective thus far, so I am securing other sources of capital, however the bonds will still be available for purchase until September 1st. 

[Ben Walsh (beamer)]

I am potentially interested in buying more bonds, however, I need some financials from you ...

How many customers have you had so far, what is the total revenue from them and what is the total profit ?

[NetTecture]

I can only wish you luck with that and once I havel ess stress we should see what you do marketing wise - I may be able to replicate this on our side of the globe (europe based) and we may be able to strike things in two markets... possibly with the same technical basis.

I am with luck (final negotiations with the power provider are happening while I speak this) signinf the lease on our data center. We got 350 square meters for a decent price (will be co-used by some import/export venture I am playing with) and a contractual guarantee to draw up to 500kw power from a trafo station that is 20 meters away Once we sign that, until end of August I plan to being 2 racks of 48 cards each online - then seeing how it goes on the AMD front either adding 48 per month, or waiting a month or two for the 7xxx series.

As a note: you can safely draw more than 80% of the amperage of a fuse.... if you prepare for that from the start. Most wiring is not prepared for that.

Together this should be a significant capacity either for mining or as OpenCl cluster - the later only needing actually customers.

[Ben Walsh (beamer)]

Is your company floated / going to float on GLBSE ?

I can only wish you luck with that and once I havel ess stress we should see what you do marketing wise - I may be able to replicate this on our side of the globe (europe based) and we may be able to strike things in two markets... possibly with the same technical basis.

I am with luck (final negotiations with the power provider are happening while I speak this) signinf the lease on our data center. We got 350 square meters for a decent price (will be co-used by some import/export venture I am playing with) and a contractual guarantee to draw up to 500kw power from a trafo station that is 20 meters away Once we sign that, until end of August I plan to being 2 racks of 48 cards each online - then seeing how it goes on the AMD front either adding 48 per month, or waiting a month or two for the 7xxx series.

As a note: you can safely draw more than 80% of the amperage of a fuse.... if you prepare for that from the start. Most wiring is not prepared for that.

Together this should be a significant capacity either for mining or as OpenCl cluster - the later only needing actually customers.