You might also want to consider this in on one of the alt-coin forums. The expectation here is Bitcoin mining, and hence SHA256 rather than scrypt mining hardware.

While I haven't tried to verify your specific numbers, I think the overall point you make is pretty accurate.

While I might be wrong, I don't think there is a direct way that somebody, outside of Bitfury, can measure their hash rate. The global hashrate, and any outside estimate of their hashrate, is based solely on how quickly they solve blocks. I think the only thing you can conclude from a reduced block solve rate for Bitfury, is that they have a smaller fraction of the estimated network hashrate.

So it's kind of a circular answer. So many things are based solely on block solve rate.

Try it if you think it will be fun, instructive or interesting. I'd be stunned if there was any way to do anything but lose money with this approach. Have fun, but don't expect to even cover a small portion of your electric costs.

You might want to try one of the alt-coin forums for better answers, though not more profitable ones.

I was just looking at the chart of past increases, and on December 18th, difficulty was 93.5 Billion. On February 19th, it had risen to 163.5 Billion. That's almost exactly a 75% increase in 2 months time. I don't have an accurate recollection of BTC price on December 18th, but I am sure it hasn't gone up 75% in the last two months.

Rather sobering in my opinion.

The original post for this thread indicates that a guess of +1.0 would go through +1.19%, and not the previous 1.09%. That suggests intervals of .2 rather than .1. Is that a typo, or a deliberate  change in the plan?

While this may be a "downer" question, what does the electric company pay you for the excess electricity that you you provide to the grid? I ask this, since from a strictly economic point of view, that will effectively be the "cost" of using it to power your ASIC mining operation. If you ask an economist, they call this an "opportunity cost", because if you didn't run a mining operation, that would all be "income" to you you. In other words, if you forgo some income to run an ASIC farm, that is a "cost".

I don't mean to rain on anybodies dream, just pointing out that if by some chance they were "paying" you say $.15 per KWh, then it might make more sense to skip BTC mining altogether. 

I would also ask, what is your current large solar farm power at the present time? If you are presently producing 475KW/hour during the daylight hours, presumably some or all of that is to power something other than Bitcoin hardware, and recharge the batteries for night-time, right? If you put in a large ASIC farm, will you just end "starving" whatever you are currently powering? It would be kinda silly to have your ASIC farm use all your solar capacity, just to find that the non-ASIC power demand ends up using equally expensive electricity.

Just something to consider.

I think in economics, they would call this an "opportunity cost".

What I have always found kinda confusing is how people view the "difficulty adjustment mechanism". My view is that it is primarily a means to control the creation of the currency over time. Come hell or high water it's going to do it's best to make sure that until the next halving we add 3600 BTC to the "money supply" every day. It makes this adjustment every 2016 blocks based strictly on how long it took to "mine" those blocks. Folks have thrown incredible amounts of hash rate into mining with associated expenditures in electricity and infrastructure. This is what has led to a multi-thousand fold increase in difficulty in the last 2+ years.

Other folks seem to think that is central to "securing" the network, along with "decentralization" (whatever that means to you). I have no real idea as to what is required to "secure" the network, since there are a variety of threats that you could be concerned about. All of which might have different answers. I can't believe that "more expended hash" per transaction is the answer in general. It's also NOT obvious to me that the infrastructure we have today, and it's expected growth, is truly required for the current transaction volume. Right now, and probably for the next decade or more, it's all about the "block reward", and the transactions are just a sideshow.

I think the difficulty is way to high for the purposes of securing the network. It's hard for me to see what would have to happen in order to actually reduce the difficulty in any meaningful way given the current investment in infrastructure. It will have to be some gut-wrenching reduction in infrastructure for that to happen.

Your electricity price is excellent, possibly almost "too good to be true". You'll want to verify that your figures are correct, and you aren't off by a decimal point or two.

You'll also want to find out what your limits on this electricity (e.g. time of day, only 20 KWh per month, etc.) are. Also take into account the bigger you go on hashrate, the more heat and noise you will have to contend with. Will that impact you, or anybody else nearby?

You could easily buy way more mining capacity than you could actually deal with, even if you electricity bill is low.

As an example, if you are thinking of an S7, consider what it would be like to have a 1300W hair dryer running there round the clock. Will the noise and heat be a problem? I will also assume that you have reliable Internet access at the same location?

+22.4 = alh

I may be a bit late, so drop me if I don't fit. Actually I really pulling for the -50% guess. I wonder how much hash would have to disappear for that to happen?

I have a couple of what will probably be simple questions. My Avalon6 is currently in transit, so I thought I would get the RPi environment all worked out before it arrives.

I started with the image that was provided by Notlist3d. This a bit shy of 4G and was rigged for DHCP. I got that flashed onto a card, and Model B Pi that I have seemed boot just fine. I was able to get in via the web interface using just "admin" for the Id (no password). Obviously a bunch of stuff is blank/empty since there is nothing connected to the USB port. All looking good.

What I have found so far is a NO way to "Shutdown" the Pi from the web GUI. Maybe its buried somewhere and I am just not seeing it. I am really reluctant to just yank the power on a Ri for fear of corrupting the SD card. I found a Reboot button that works great, but no "Shutdown". Any comments/thoughts?

I then thought I would do the "Set a password and enable SSH" thing. I am really not understanding how to correctly operate that page. I can enter a password and confirm it just fine, but it seems to have zero effect. I am also confused by the Id that I am setting the password for. Is it "root" or "admin". Any comments on the userid/password structure that is in place would be greatly appreciated.

I also looked at the ehash website and found a variety of firmware versions, all from different dates. I also see multiple files for each date. It would be really good to know exactly which one I need to flash, and what it's expectations are in terms of network environment (DHCP, Static, etc). I am also surprised by the fact that the largest one is but a mere 76Mbyte in size, way smaller than the 3.9 Gbyte image I started with. I can obviously try some of these things to see what happens, but thought I would see what the collective wisdom is one some of the more mundane "System Admin" tasks for the Rpi in this environment. I have a comfortable grasp of Raspbian on the Pi, but OpenWrt is way new for me.

I think it's still important understand that phrases like "game changer" and "stand against the halving" need to be taken with a grain of salt. While for most folks, the halving will appear very similar to most folks like a 100% increase in difficulty, it is different in several ways. One is that while difficulty can decrease, there will never be an "un-halving". The decrease in the block reward will last until the next reduction. We won't ever go back to a block reward of 25 BTC. While it's theoretically possible for difficulty to decrease by 50% (which effectively "un-does" a 100% increase), I don't think we have ever seen that in the past.

Folks need to remember that in the long run (i.e. years), mining (or transaction processing), will migrate to locales with the lowest electrical costs, lowest cooling, housed in cheap real estate, executing on the most efficient hardware. There is no magic ASIC geometry (i.e. 14 nm), or efficiency level (i.e. .06W/GH), which will insure you an indefinite operating profit unless all the other factors mentioned apply. Very efficient hardware can make a once unprofitable location profitable for a while, it's strictly transitory.

Late night update from Minnesota (USA):

Bitcoin Difficulty:    144,116,447,847
Estimated Next Difficulty:    176,532,440,090 (+22.49%)
Adjust time:    After 1482 Blocks, About 9.1 days
Hashrate(?):    1,237,126,110 GH/s
Block Generation Time(?):    
1 block: 8.8 minutes
3 blocks: 26.4 minutes
6 blocks: 52.7 minutes
   
Updated:    1:5 (5.2 minutes ago)

BTC Price: $375

Not looking so good for the "Mining Team" at +22.5% !!! 

This going to get old real quick.......

Thanks for making this available! It's unfortunate he doesn't indicate how many chips you get if you put up $1M.

Do you get 100, 1000, 500,000, what?

Nice way of saying "Don't talk to us unless you have serious money". Not a surprise.....

Pretty much for the same reason that they would pay $39??? This device doesn't pay for itself under hardly any circumstances, and the price difference will have no effect either way. If you play the lottery, do you worry if the ticket costs $1 or $2? Same principle.

I was thinking about Phillip's 3rd Avalon6 group buy, but things are looking quite "un-rosy" for me. My electricity price of about $.10/KWh is just not going to cut it anymore. I'll throttle my SP20 down a bit further, but that's just a month or two delaying action. 

If the two folks that seem to know what's up with Bitfury are right, and not outright lying, Bitfury has NOT received their first full wafer of 14nm chips (i.e. something larger than samples). Supposedly they get those late this month. That means we have not yet seen a spike resulting from a significant deployment of Bitfury 14nm ASICs.

The most recent hash rate increases are clearly real and likely here to stay. While it would be nice to think the most recent 20% increase will be followed by a small one, I see hash rate, and hence difficulty rising right on up to the halving. I don't expect that they will all be 20%, but there aren't any negative changes on the horizon that I see. 

Just one mans speculation late on a Sunday afternoon in Minnesota.

Here, let me ponder on that for say 2-3 milliseconds.......

I predict that difficulty will rise. My "Magic Eight Ball" refuses to give me a precise number!!! 

Bitmain has reduced the price of the latest batch S7 miner. The Batch 10 S7 is priced at 2.1 BTC, which is less than $800. The biggest drawback is that you won't get it until roughly February 20th at the earliest. Chinese Spring festival, so Bitmain is on "vacation" until that's over. That will also push down the price of a used S5 as well. See:

https://enshop.bitmain.com/productDetail.htm?pid=00020160129054250700R0OMI3KI061A

While I have "no dog in this fight", their offer sounds vaguely familiar. Didn't Butterfly Labs (aka BFL) offer their Monarch customers some kind of cloud mining deal as compensation for the horrendous delays?

Well at least Black Arrow didn't offer an upgrade to their X72 (i.e. twice as good as the X36) product for a modest fee. You could be the first one in line to never receive anything!!!