Just a side note, you save like 10Watts going from HDD to SSD, it's not like some super huge mega power saving device. The two main power draws in a system are the GPU and the CPU, fans/harddrives/whatever are minor additions.

GPUS definitely do draw power from the PCI-E bus, don't kid yourself there. Many newer boards however have power options designed to draw additional power from the PSU to the board however to offset an increased load. It's still pretty harsh on a system to run that much through it.

Sarcasm aside, some sort of source is required for discussion.

I'm curious about peoples predictions of what happens next.

Difficulty is bumping up 50%, meaning drastically reduced mining rates for... everyone. Price seems to have stabilized / capped around 7USD per bitcoin for now.

Will the price shoot up to offset the difficulty again or will it remain stable/drop in response to people dropping out of the bitcoin game?

That case is terrible and the power supply is way more than you need. For 4 cards you're better off running caseless. Oterhwise you will have to get something huge like an HAF X or Rosewill Thor.

Save yourself $50 by getting an HX850 (you could do with a750 but this one is a good deal), and a better case, and 4x5830s if you cant wait for 5850s to come back in stock (5830s have possibly the highest MHash/$$ ratio right now, but they're somewhat weak overall and have high power draws comparitively).

I'm still playing with building myself, but you certainly make a good point about wire shelves. I'm looking at 'tech benches' at the moment, seems a nice compromise between case and no-case (I don't feel entirely comfortable having a board not securely anchored, but I'm kind of a huge wuss).

P.S. I never said thanks for this article, I built most of my stuff before I read this but it was still a good read nonetheless

Nah, if it were then ebay, paypal, most online stores, etc. would have gone defunct a decade ago. This is just one of the major growing pains of a new and popular service, that the community needs to take time to work out. When EBay first started out it was scam central, kind of a wild frontier, and over time it got refined in such a way that it's (perhaps excessively) safe. There will always be people looking to get something for nothing, fleecing sheep, just one of the sad little lessons of life, but I think most people understand this, and as they become more familiar with a service and safeguards are made easier and more readily available it will be less and less of a detriment to the service as a whole.

In relation to OP, there is a quote I enjoy:

"You cannot cheat an Honest man."

Sadly I'm not an honest man, but it's a good concept to keep in mind.

Your math also doesn't account for secondary costs. Aside from the 2 million USD of hardware (assuming you can find 1,628 5970s in short order, no small task), 407 machines running 1,628 GPUs would likely eat roughly 610 KiloWatts of power, requiring 5,087 Amps (or if you were on an industrial power grid 2,543 Amps). Either renting out expensive space at a data center or building a custom housing/generation complex would be required. Additionally 610KW = > 2Million BTU/hr, requiring some form of cooling to the tune of being able to remove 2 Million BTU. Custom networking and so on.

It obviously wouldnt be tens of millions more but there are lots of additional costs to running huge farms of machines.

I am running 2x 5870s overclocked to 975MHz and a slightly overclocked sapphire 5850 (I've downclocked the memory to 300Mhz on all of them) in my big box. It puts out about 1.1GHash/sec and pulls 555Watts from the wall. Assuming an 87% efficiency rate that's 482Watts. So 2 5870s should be able to run on a 500W PSU.

One thing I will disagree with. That motherboard is stupid. Incredibly stupid. The layout is such that the 3 PCI-E slots are packed together incredibly tightly, with the horrible "push-clip" securing style, and to top it off, the placement of the case connectors and SATA ports are right next to the 2nd and 3rd lanes. This is ok for the sapphire 5850 xtreme, as it is a very small profile card, but a slightly larger, more powerful card will be completely unable to fit due to this stupid placement.

I have some other complaints, but I can't remember them at the moment, as I just threw my hands up in the air after I managed to finagle some things together that wasn't totally awful. So, it can work, but it's really not ideal.

My favorite board thus far is the MSI 890FX-GD70, you can find it a little cheaper than a new assrock if you're lucky and it gives you a whole lot more niceities, even if its a slightly older configuration.

If I were a smart day trader I definitely would have done that. Sadly I'm just a lowly miner, *cough cough* sorry, coal dust in my lungs.

EDIT: The real winner right now though would be Mt. Gox, imagine all the madass trading going on right now between panic'd coin holders and shark speculators. Ha.

It dropped below 5.85, then jumped back up above 7. I would say the $9 bubble burst (temporarily) but it's not like bitcoin suddenly got totally annihilated, calm down. I get a funny image of OP in the 1920s causing a run on the market. But this should at least serve as a reminder to people that unprecedented growth does not continue forever, at least not in the short term.

I expect there to be some voltaility as people like OP panic, but if it will totally crash, this I doubt.

How are your cards configured? Might be thermal throttling as well, if you've stuffed all the cards close together.

Unless he has a signficantly inferior PSU this is unlikely to be the problem. Running 2 5870s OC'd 100Mhz and a 5850 OC'd 100Mhz with downclocked VRAM (make sure to do that OP) and a CPU @ 100% load, a few fans and an HDD my rig pulls 550W from the wall, which is probably closer to 475W from the PSU.
This is a significantly higher power draw systsem than 2x5850s and a 5830, which would definitely not draw anywhere near 600Watts.

Not all 6950s are unlockable, only reference 6950 2GB VRAM models and like 2 non-reference (that I cant rmeember off the top of my head) can have their shaders unlocked. The card will then need to have its bios flashed either to 6970 (can be dangerous) or have their shaders unlocked (less dangers, requires overclocking manually to 6970 levels).

Depending on the price you can find either card for will depend on which is a better buy for the money (typically 6950s are more expensive and require overclocking to reach stock 5870 MHash/sec), but if you want to game the 6950 will offer a more efficient and future proof card (it has better tesselation features, superior crossfire scaling, more VRAM etc.)

An idea that I'd been tinkering with myself in the past (although I was planning to personally fund it all from start to finish, but a distributed investment idea is very clever), that seems pretty feasible really.

One thing I'm not sure if you've factored in though aside from the raw power costs, which will actually probably be much lower than you anticipate (3x 5850s can generate 750 - 900MHash/sec and use about 500W for the whole system for example depending on overclock), is physical presence.

The 30 rigs you propose will need to be housed, that will require the physical space for 30 rigs. They will need to be powered as discussed as above, and in a typical household a circuit breaker can handle a maximum of 20A (in US, 120V*20A = 2400W), as well as having a main circuit which can handle between 100A and 200A for the whole house depending on how it was built (12,000 - 24,000W total for house), 30 * 500W = 15,000Watts (21000 if you really use 700W), or in otherwords even if you managed to split the rigs across every breaker, it's possible the house would then not be able to run anything else, like lights, refrigerator, dishwasher, microwave, etc. Speaking of other things that take power, cooling is one of them, 15,000 Watts is actually nothing to sneeze at, 15,000W-hours equals 54,594BTU. An average 3 bedroom 1440 Sq-Ft house would only utilize about a 41,000 BTU heater for the whole house (and you'd be running your 54.5kBTU heater 24/7), meaning you'd need to utilize a lot of airconditioning, adding both to the cost and power load (which you might be squeezing already).

Not trying to shoot down the idea, I of course like it, but just trying to throw out some other possible stumbling blocks you might hit upon as you aim for the future of the project.

Damn, I'm really tempted towards buying one of these, I like the idea of a bitcoin buy, and I'm pretty much local so I could pick up, but I'm not sure I can justify $900 right now (and I'm guessing since you're in CA you'd need to charge sales tax )

I picked up 2 HAF series cases, and since the reference coolers are almost entirely shrouded, the high case flow provides almost no benefit, so I'd almost welcome a reason to have invested in the case 

Very cool looking project, I was considering trying my luck at solo mining when I got up to a certain level of processing power, but this looks like a good balance between solo and pooled efforts, so if there is functionality added to warn when workers stall (an annoying problem I face fairly often) I'll probably switch all my workers over to this for a few days to see how things operate

I'm in CA too so latency should be sweet, and I read recently that deepbit got 50% of the processing power, which I think is a poor idea, so alternative pools just make good sense (if you can be patient enough to not have all blocks solved right away).

EDIT: No more superman 2 decimal profits for server? Aww heh.

It's funny how this thread turned into a 6990 thread rather than an OS thread.

I had a quick question about the starting topic though heh. How much more stable is linux compared to windows in general? I'm currently running some dedicated mining boxes on windows and I am currently still working out the kinks of heat and whatnot, so I get about 1 crash per day.
Is that because of windows and I'd get better results in linux, or is my thermal / overclock too high and it's my fault? (running 3x 5870s in one box unspaced, OC'd to 975MHz, top card can getupwards of 90C, but I've also had occasional crashes in a spaced rig with temps closer to 80C).

You know that's not a half bad idea, I have a bunch of reference 5870s, which are awesome for overclocking, but the downside is the cooler is like a damn leafblower. I was considering water myself because I'm sick of potentially going deaf (and if I don't go deaf I get massive hardlocks, bringing down my system, costin me monies). I hadn't really considered popping off the cooler and replacing it with a relatively inexpensive aftermarket cooler, sucks that it messes with my profit margin, but it probably messes with it less than building a big ass water rig will.

I'm not sure how people are building $150 water coolers, unless you're only cooling a single card?

I'm currently using 1/2 W 68Ohm resistors, they fit perfectly into the plug and have yet to short out and destroy my rigs.