So I have bought this bot for me. During last month is was totally unprofitable, see chart below. I was using dedicated btc-e account for it, so nothing else could interfere.
http://s24.postimg.org/l29qiklcj/btcrobber.png

Yep, everything is right. With these settings bot would sell everything on 5th. As the price had huge drop after that - you actually should be glad that this happened
Also, with current trend and these settings bot will buy all BTC back within few hours

In reality people will adjust their EMA constants every week or so, resulting with bigger profit then year long simulation with the same configuration for all period. Also, bot would earn some profit  even in case if btc price do not rises, but just fluctuates around certain value. This is huge difference than saving btc.

Another thing is that with EMA strategy you are protected against btc price drops. When price drops - bot simply converts your goods to usd. When price rises - goods are exchanged back to btc.

Like this morning when I saw huge BTC rate drop during last day - first thing I have checked is how much did I lost on my btc-e account. My bot configuration now is rather ok, but I did lost around 5% of usd value, until bot converted btc to usd. But its much less then losing 40% like those who just store btc. And awesome part is that if price will rise back to the old value - I will get these 40% as profit.

Soo, thank you Butter Bot, you are doing great job

Anyway, considering linear difficulty increase per period like 100kk, 120kk, 140kk, 160kk, etc..., with rates 0,2 usd/kwh and 750 usd/btc - profit would be something like 450kk in 6 months, pretty neat.

3 @ 3 BTC
well, I know its against your minimum bid, but in case if you change it - you can count on my order

No, I would not. You see, you have chosen very bad time to enter ASIC market.
Although now you specifications look amazing, in December and January a lot of new companies will start to deliver their devices. Difficulty at that time will go up, up to ten times more than current. And any ROI prognoses with current increase rate will be wrong starting from year 2014. Your device delivery in April is so late, and so far away, that risk is very high. Your offer will be accepted only by guys with big pockets, who invest into everything that possibly can mine.

My background - I am just watching hardware forum for half a year now, trying to follow any related news.

BFL tought me that even totally legit company with all that government paperwork and stuff - still can fuck you over. And that any ASIC order should be paid with PayPal, they can sort things out and force refund.
Its a shame that device for bitcoin minig should not be paid by bitcoins, though.

Nope. They were wanking for more than a year, but now everything is somehow in delivery stage. Last time I have checked - everything from year 2012 is already shipped to customers, so they have only nine months of orders to deliver . And they constantly ship devices, all this is legitimate, nobody is screwed. Except fact that nobody who will receive now their device will make ROI. I am sad for guys who ordered 500GH/s device :/

But still, they have huuuge amount of TH/s to deliver, and they can keep difficulty increase on any level they want. This sucks.

Difficulty is increased because of added new mining devices.
As I know - mining devices now are produced and shipped in big quantity only by BFL.
Last 4 increases all were around 30% (29.4% - 32.22%). This coincidence (almost same percentage increase 4 times in a row) never happened before.

Does it mean that BFL specially ships devices not in their full potential, but in specially calculated quantities to keep this 30% increase ratio?
And, possibly, all who are now still waiting for their BFL device - could have them delivered month ago if only BFL would ship all at their full potential?

But I want to have free bitcoins!But I want to have free bitcoins

I want to buy an ASIC for me. I started to check what devices are now available on market and tried to calculate their profit...

I have assumed best case scenario for difficulty increase - 30M for next period, and then additional 5M for each consecutive period (this is tendency for few months already): next increase will be 30M, then 35M, then 40M, etc

I have compared ASICs from page http://mining.thegenesisblock.com/.
With difficulty increase described above - everything is perfect for almost any new device that comes online in late 2013 and early 2014 (except BFL, even in best case their Monarch will take two ears until ROI).

But, its not like having only one existing device of that type in the world. In reality as soon as these devices will start to appear online - difficulty increase will become huuuge comparing to current. Cointerra promises to deliver 2000TH/s in December. And now whole BTC network is only around 806 TH/s. And there are at least 3 more companies that will deliver another huge amount of TH/s in few months.

Soo, in January 2014 any currently available ASIC will become worthless, right?
I suppose there is only one option - to wait for new type of Bitcoin miners, that will be superior to ASICs?

Actually this is lowest $/GH ratio available on ASIC market (excluding other BFL cards). Next one is KNCminer Jupeter with 12,48 $/GH (with preorder for November delivery). If BFL will activate this service even on February - these options are sort of the same by profitability.

BFL is very good at marketing and have great vision of future. Their delivery totally sucks, though. But everything is already foreseen by them.

Soon difficulty will skyrocket with cosmic rates. To keep stable income from BTC mining - one should buy new devices every month (and $/GH ratio will drop a lot in future to keep buyers, so amount of bought devices per month will grow). Does anybody want to have hundreds of devices in his room, and maintain all this stuff? Nope. Its much easier to buy mining contact - pay money and receive mining power instantly, without shipping and device setup and etc.. Plus, this is better for ASIC producer too - they do not need to process all these orders with shipping and packing. Just receive chips from manufacture, assemble on board, plug board into server rack.
Soon ASIC producing companies will start to switch to this contract delivery model. They must be stupid to leave this opportunity. And BFL does this now not because they have technology, but just to establish themselves as general provider of such service. Real result will be provided by them in two weeks after publicly announced date .
Its just their work model - promise thing that will be demanded in future, collect invests, promise, deliver when its not relevant anymore.
It looks totally promising, just don't invest anything until you will see that this service is online.

Nice, thanks! Пoздpaвляю c ycпexoм!

What type of heatsink does 25GH Miner Starter Kit need? Is it ok something like 16 small heatsinks without fan?

Wisdom in its finest form


Dear everyone-who-now-has-changed-his-mind-and-want-a-refund,
Stop acting like child and start to sell your preordered BFL units on ebay. Let me help you: http://www.ebay.com/
Thank you for your cooperation.

Best Regards,
PaperClip

They have sold units with no refund policy as of day 1. Even with this policy, it was possible to ask for refund and they were accepting them. Then they have double checked order status with every customer, providing refund to everyone who wants, notifying that refunds will be completely canceled soon. Is it not enough? Maybe they should have go to every customer doorstep to personally tell them "do not wait for your unit for 4 more months, take back your money instead"?

And now after all this - somebody thinks that he is special and all previous communications and notifications are not applied to him. Are you serious? Where have you been 2 months ago, when difficulty scyrocketed, and BFL was considered as scam? Now it is even better situation for BFL customers than before, they have a lot of confirmations that company is not scam.

Yes, correct.
Actually, equation for "Estimated new diff change" is larger, and involves difficulty. But it can be simplified to that simple form.

(D-B)/(C-A)*2016 is time (in seconds) that will be needed for full round, according to current average speed.
60*60*24*14 is ideal time for full round in case if network hash speed does not change. Basically, average hash speed from last round would take this much seconds on current difficulty for this round.

DIF - current difficulty
DIF_NEXT - next difficulty

next difficulty can be calculated from this:
DIF * (60*60*24*14) = DIF_NEXT * ((D-B)/(C-A)*2016)
or
DIF_NEXT = DIF * (60*60*24*14) / ((D-B)/(C-A)*2016)

Increase = (DIF_NEXT - DIF) / DIF
Increase = (DIF * (60*60*24*14) / ((D-B)/(C-A)*2016) - DIF) / DIF

if you simplify last formula then you will get
(target time) / (average time per block * 2016) - 1

allchains.info use linear extrapolation method, you can easily do all these calculations by yourself:

1) go to http://blockexplorer.com/q/nethash/2016, take latest block number (currently: 243936). This is first block after difficulty change.
A = 243936

2) go to http://blockexplorer.com/b/243936 (or insert new block number from step 1 in case of difficulty change), click on "Raw block" link, copy value from field "time" (in this case: 1372515725). This
B = 1372515725

3) now take block number from step 1, add to it any value between 1 and 2015. In this case it will be 126, or 252, or 378, etc..
C = 243936 + 126 = 244062

4) go to http://blockexplorer.com/b/244062, click on link "Raw block", copy value from field "time" (1372584672)
D = 1372584672

Result formula:
(60*60*24*14)/((D-B)/(C-A)*2016)-1
Result is 0.096494409, that is ~9.65%


I don't know about http://bitcoincharts.com/ algorithm, unfortunately it is impossible for me to find missing values there. Anyway, with allchains approach difficulty increase estimation every 126 block is following:
126 (1/16): 9.65%
252 (2/16): 9.98%
378 (3/16): 10.04%
504 (4/16): 9.65%

I also had idea to submerge miner into oil, but in the end decided to avoid this. A/C will be enough for one device like in my case, and its not so safe to place tank full of hot oil in living room.

Anyway, you may find this advice useful:

As I know only 5GH/s unit is shipped with power cable, all other use power from separate PSU. Maybe 500 GH/s unit is shipped with power cables too, at least it looks like standalone device with its own PSU.