With 1CRedit that is easy to compute.  Look at the current block number.  1 coin per block, no pre-mine!

3 days, 16 hours for me with 2 units:  4854 and 4845.

I am rather surprised by the volatility though.  Here is a chart from BitcoinCZ with my (2) S7s, (3) S4s, and (1) S3:  http://puu.sh/kOKPC/e46870370a.png

Actually, Texas is rather overbuilt with datacenters, especially Dallas.  If you wanted wholesale space, say an entire suite of 7200+ square feet, and provided your own racks, you would likely pay $130-$150/kW/month.  The "no bitmining policy" have sprung up due to data centers being left out in the cold when prices dropped.   I've been in centers with rows of S1s powered down - just abandoned with back rent due.  The mining company folded and left the datacenters to suffer.

If you expect the data center to provide more than space, power, and cooling (like racks, network gear, overhead cable trays, etc.) - expect to pay more.

Note that every colo has their own pricing model.  Some charge for space, some for power, some for both.  Some measure power by metered rack, others charge by power whip, still others include a base usage with a cap.  Some require you to pay for a "reserved" amount of power you will never exceed.  Some have fairly heavy setup fees, some roll that into their monthly charge.  All want long term commitments with a 3 year lease being the minimum and a preference for 5 to 7 year leases.

If you can find a new data center built about 3-5 years ago, you may find one with excessive power capabilities that will cut you a deal.  Many data centers back then figured new clients would need 8-12kW/Rack, when in fact, most customers average about half of that.  So they have power grids, UPSes, and Generators designed to support about twice as much power per square foot than what they can sell.  Power hungry bitminning could help them balance a bit.  Downside is that most of those folks also built themselves concurrently maintainable space with 100% uptime capability.  That is a feature that cost money that bitmining doesn't need nor does it want to pay for.

Yeah... I help find data centers for companies for a living...

At $0.0535 kWh ROI is VERY questionable.  I'd never even try at the $0.12 kWh cost out at our farm, much less at $.31.  Now if you have excess solar and are not grid tied with power credits, then maybe, since you have already paid the solar cost.  But chances are you would only be able to run for hours a day, not 7x24, so much less likely.

I think I'm at the point where I'm just going to look at my BTC wallet, subtract that monthly cost in power, and see if its positive or not!  I use BTC for all my mining and related computer cost.  As long as the wallet looks good, I'm happy.

Guess I'm lucky.  My power cost $0.0535 kW/h so a S7 cost about $1.87/day to run from my home (that including 20% overhead power for room fans).  Even so, the math I just did indicated a 232 day payback for my Batch 1s.  Of course, that is optimistic since it presumes today's difficulty for the entire time.

Its almost humorous, but the only thing I have that has ROIed is my Batch 9 S3s.   I make about $0.46/day real profit on each of them.  Woo woo!

The math is actually trickier than it appears.  For instance, since I paid with BTC, if the value of BTC goes up, so did my cost... right?  Or should I lock in price based on BTC value when I bought?

DHL was a little better.  No notification from Bitmain, or responses to my tickets/e-mails, but DHL texted me on Sunday (then it got hung in customs for an additional 2 days).

My 9/2 order arrived today.  Both are powered up and running at 600Mhz, yielding ~4.8TH.

One is at 4.822TH, the other at 4.886TH - but they have only been running a few minutes.

I'm pushing my 30amp 220V power strip to the max with (2) S7s on one half and (3) S4s on the other half.  So close that I had to downshift my S4s from 200MHz to 187Mhz to keep from popping the internal breaker.  Suspect I'll move another power strip into the room and split the load.  I don't like running circuits over 80%.

I'm using the Bitmain 1600W power supplies, which appeared to have nice long PCI-E cables, but it was closer than I liked.

I did notice a howling sound from one unit.  If I put my hand close to the fan it changes the sound.  Ended up putting a small block of wood about an inch in front of the intake fan to keep it quiet.

FYI:  My 9/2 order cleared customs this morning.  Arrived there Sunday night - so a 2+ day delay.

Congrats.  I just got a note from DHL that US Customs didn't work yesterday due to Columbus days.

I called DHL this morning.

Package is stuck in Customs in Cincinnati.  No progress since Sunday night.  The status went from an estimated delivery yesterday to "unknown".  Apparently Bitmain called and started a trace yesterday, due today.

I choose DHL because of Customs warnings with FedEx, and paid a higher shipping charge due to that.  Is UPS any better?

Looks like my 9/2 order is stuck in customs in Cincinnati.  Although DHL claimed a 10/12 delivery, its now 9:30pm local and I think its safe to say its not coming.  No update on the DHL site since yesterday at 5pm.  Last status was "Clearance event".

Bummed.

Have you done any BTU to CFM calculation for ventilation?  Any other math?  Having the same thought - looking to supplement my homes heating this fall and winter.

I suspect what we really need is some form of hot air containment combined with the CFM ratings on the fans to balance things out.  The specs say they use 12038 fans, which push about 80 CFM one push, one pull.  Does that mean 160 CFM total or is that double counting?

I found one of these:  http://www.thelashop.com/6-400-cfm-inline-duct-booster-vent-fan-blower-aluminum-blade.html?gclid=COjL7PHsvcgCFZCCaQodPtADtQ  which I could rig with a T and blow the hot air into a house vent above my server room...

I'd say that is pretty much a rule.  Few, if any, houses in the USA have oversized wire in them.  Replacing a 15amp breaker with a 30 amp one, and then loading it, is a great way to start an electrical fire.  Its also not going to get you 220V in most cases, since any 220V breaker is a "double" (since it has to span both legs inside the panel box).

Hmmm.  Using BitcoinCZ stats as a basis, my current 6.7TH of ASIC farm ((2) S3s, (3) S4s) pays about 0.005 BTC per found block and that pool finds half-a-dozen or so blocks a day.  If I'm doing the math right, if I solo mined BTC and had average luck, I could find a bit under 1 coin per month solo mining, or 25+ months per block.

Is that what you recommend?  Run for 2 years and hope I find a block, with nothing in between?

Seems to me that unless your spending thousands a month in electricity, pools are not really an option anymore (e.g.  "not an option, a necessity").

Me too, 09/02/2015 date, but was contacted by DHL and am expecting mine yet today.

I ran mine straight from the panel, with the 10 gauge wire required for a 30 amp circuit, into a new 30 amp 220V breaker.

FYI:  Within a US household and associated typical run lengths:

14 gauge wire (often with a white covering) is rated for 15 amps
12 gauge wire (often with a yellow covering) is rated for 20 amps
10 gauge wire (typically with a black covering) is rated for 30 amps

voltage doesn't matter with regards to wire thickness - at least at the voltages we are talking about.

All of this, including how to install such a circuit, is available in a ~$10 book on wiring available in most Home Depots or Lowes type stores.  Of course, only do what you are comfortable doing.

Hardly.  I'm USA based and simply dropped (2) 30amp 220V circuits onto a wall and run PDUs from them.  Bought some power cords to match online and have been riding golden on my mining equipment every since.

I agree with the advise, of course... and I didn't follow it.  My reasoning was flawed but A)  I was expecting a shipment  B)  They identified the sender, basic product, and price category  C)   It was end-of-day on Saturday and I didn't want to risk further delays  D)  Compliments of the recently announced Scottrade hack, I have 1 year of credit protection services.

Obviously, I'm going to seriously regret doing this if it was a crooked DHL employee gathering data for resale on the black market.

Mostly I am just curious if other Bitmain customers ordering 2 or more units and shipping via DHL received such a call?

Sorry - Social Security Number.  The one thing most of us USA folks have been trained to NEVER give out over the phone unless you know who is calling you (like your stockbroker!).  Its the foundation for identify fraud here.