Almost all miners are built to run at room temperature, cooling below 15C is the realm of overclocking and overvolting

Importing miners into Canada I had to pay 5% GST and was happy to do so. In much of Europe you will pay up to 20% value-added tax. It seems to me that your state (In the US obviously this will differ from state to state on what goods and how much tax is owed) has some kind of import/sales tax and your miners will almost certainly qualify, especially in an amount that would require $15,000 worth of tax!

It is up to you to determine what taxes may be applicable and what rate is applied in your state.

According to http://www.taxrates.com/state-rates/arkansas/ states that depending on municipality you may owe between 6.5% ($200,000 worth of miners!) and 11.25% ($180,000 worth of miners!) sales tax on imported items

Either way I'm impressed with that number being hosted in North America

Interesting side note: In Canada bitcoin generation is GST-exempt (receiving bitcoins by mining). Receiving fiat for bitcoin amounts to capital gain at a minimal tax rate, all for some very good reasons. However I determined that hosting services ie. hosting someone else's miners for a % or flat-rate fee would be GST applicable at 5%.

+4.9 = Erumara

There has been a lot of debate about this, even a desktop PC will release *some* voc's during it's lifetime. On the plus side it's been agreed that a 1500M household air filter will negate any potential exposure.

Not having to dig through dozens of thread pages is why I went and asked the question

In any case I finally bit the bullet and did my studying and got stratehm proxy running; and all of my problems seem to be solved. Running the proxy stratum during today's ~2hr downtime on the sha256 stratum answered a lot of questions too, I watched the stratum bounce on and off every few seconds for the duration of the downtime, I was able to force through a few shares but at great cost to the units overall hashrate.

It's no wonder the s7's choke on the connection, it's off and on a few dozen times a minute with the miner connecting and sending shares and getting rejects and disconnects in return, cgminer just has a breakdown followed by the OS under some circumstances. I realize now there's probably a pretty deep and difficult to fix problem with the server or the protocol it's using.

Thanks again!

<Address>.worker1
<Address>.worker2
<Address>.worker3
etc....

Sorry to say that even at 24k diff I still came home to one unit locked up, and two needing reboots.

Just a nudge to crackfoo to see if there's a solution to this issue.

Still sent some karma your way citronik, cheers!

20000 had one machine lock up, had a failover at 22000 diff that they *almost* recovered from, only 1 blade dropped on one unit. So I have set them at 24000 diff and hopefully they stay up while I'm at my buddy's BBQ.

Is your profile BTC address valid citronik? I think you have some karma headed your way

I added in that algorithm line and:

Ran at diff = 16000 for a couple hours, finally connection dropped and when it restarted I had lost 3/12 blades, 1 unit needed a reboot 2 units needed a power cycle.

Ran at diff = 18000 for a couple hours, connection drops, 1 unit recovered, 3 units locked up and needed power cycles, 1 unit needed a second power cycle and a soft reboot.

Now testing at diff = 20000, I hope something friggin works this profitability today is bonkers!

Backup pool is nicehash, password: c=BTC, d=22000, failover works fine but as soon as they reconnect to zpool the hashrate drops by 1/3-2/3 while the asics all show up as working, and 1 or 2 blades will drop in temp. Sometimes the miner will soft reset itself but that rarely fixes the problem.

Have tried everything from 9000 to 26000 with the same results, anything else I can try?

Any updates on the sha256 stratums? Been testing my s7's on and off, and no matter how I adjust the difficulty within a few hours the connection has dropped and for whatever reason it will most often boot back up with a blade or two not working, really pointless to have to power cycle the unit just to use a pool; even if the profitability is nice.

Awesome miner seems to be a good piece of software, tried out the demo but wasn't about to purchase it myself.

As CLEARLY evidenced by people posting in this very thread, BTC home mining is not dead. Statements and opinions regarding the profitability and speculation of bitcoin hardware belongs in Bitcoin Forum > Bitcoin > Mining > Mining Speculation
Thanks!

Batch 8 came in a little over 5TH, but from what I've heard they are slightly less stable, not to mention they are highly sought after and thus will be trickier to obtain.

Power supply is partly preference, my research showed that a retail PSU (I would recommend the eVGA supernova 1600w) runs *significantly* more efficient than the bitmain PSU's, but at over twice the price. With a 10 year warranty the eVGA will likely outlive a generation or two of miners, and 1600w is pretty darn close to maxing out a 15a circuit so it will likely power just about anything for a while to come.
Also the retail units will happily take 120 or 240v vs. Bitmain's demanding a 208v minimum, so depending on your situation the retail unit could be the better choice.

I don't have links to the proof, however based on some videos and other research I saw bitmain units pulling 6A @ 240v vs the eVGA pulling 5.4-5.6A @ 240v, a pretty significant efficiency gain, I wish I had the wattage numbers for you but I haven't gotten around to metering my units as of yet.

To summarize:

Bitmain 1600w PSU - Cheaper, smaller, functional
eVGA 1600w PSU - More expensive, more efficient, 10 year warranty, better resale value

No complaints if you lock up this thread and we can start a new one, more than a few users tried to get this chatter moved to the proper threads but apparently some people just don't understand how a forum works. Thanks -ck!

Seems to be another nice catch Gleb, it's beyond me what they plan to do with it but it's a guarantee it won't be good.

What he's trying to tell you is "Touch the wrong thing and the best case scenario is you will WISH you had died" 

Seriously though, seeking advice from strangers who are incapable of knowing the details of the wiring in your home ie. the age of the wiring, the capacity of your panel etc. is a losing proposition.
If you are considering purchasing something as power-hungry as an S7 it behooves you to seek the advice of a licensed electrician.
Nobody wins if you decide to fudge something together and the consequences range from fire, property damage (including potentially frying an expensive miner), and, as talks_cheep was so kind to point out, a severe case of death.

I haven't had much chance to play with pos intake vs neg exhaust pressure, the way my box is setup I'm definitely keeping the exhaust suction a bit higher because there's very little downside to pulling in indoor air vs. the negative of pushing outside air into the box and into the house. Something like that will come about in a few months when I have to look at mixing the inside and outside air reliably to feed the miners air above 10°C during the winter and capturing and filtering some amount of exhaust air to feed the house.

The way you're setup I can definitely see the advantage of building a box just to control the air a bit better and cut down the noise a bit,  just remember to measure once and then cut everything, that's the trick the tradies won't tell you 

Good catch, it is an Elicent AXC 200B which *is* rated for ~700cfm, I believe I got that confused with the cfm rating of the ductwork (~1200cfm ideally, like more like 1100cfm with the 90's and duct runs accounted for.) Which I will be pushing for with a second fan on the intake side to boost cfm, add in redundancy should one fan fail, and cut down the noise by running each at ~80%.

I've played with the idea of adapting in a 10" or 12" fan which would push 900-1200cfm but I can't reconcile that cost, any ductwork over 8" I have to deal with a distributor and that's also a huge pain.