I'm going to London and seriously consider withdrawing GBP from a Bitcoin ATM.

Just need an answer, what are the fees and is it cheaper than using a VISA card (including exchange rate markup)?

A few tips:

*The Ant works well as a shoe dryer.
*Use a black permanent marker to dim the flashing LEDs.
*Put something soft under the miner to eliminate vibrations. It may make it more silent.

I'd like to minimize W/GH.

So far I've only tried OP's recommendation. My miners ended up at 185W @ 140 GH = 1.3 W/GH.

Has anyone underclocked even more, and what W/GH do you reach?

EDIT : See OP. He uses 0.85V but shows that 0,75V should be even more efficient. For 0.85V the resistance shall be between ~2.8kOhms and ~3kOhms. We should find out what Ohm that suits the 0.75V setting

I've placed Antminers around my apartment for heating this coming fall and winter. Steps made:

1. Undervolted and underclocked. 140 GH @ 185W.
2. Placed conveniently on shelves in most rooms except bedroom. Will run 24/7 as long as mined bitcoins are worth more than electricity. After this point will only run when I need heat.
3. Connected Ants to TP-LINK wifi routers. These are very stable, and are connected with cable to miners.
4. Fans were dissembled, then vacuumed the heat sinks, and then put fans back on.
5. Fans now run reasonably quiet at <1800 RPM. More silent than AC but would ideally be even more silent. Any tips?

Agree. And remember; if you buy an S3 you can still use your old S1. It will still run profitably for a while, especially if underclocked.

The price is 0.46 BTC.

It's a cool kit but VERY EXPENSIVE. I did some calculations at Bitcoin Wisdom and it will most likely make a tiny, tiny profit of 0.1 BTC or so.
And this is without taking into consideration that the S1 anyway would generate more than that if I leave it running underclocked and undervolted.

Will YOU buy the S1 Upgrade Kit? If so, what is your reasoning?

Why do so few in the Bitcoin world group digits? Wallets, exchanges, shops, almost all forget it.

I'm tired of seeing 0.00158 BTC. Why not write 0.001,58 ? Or 0.001'58 ?

I vote for the latter!

Another example : 1235.12354823 = 1'235.123'548'23

I've invested about EUR 2000 in mining hardware and paid about EUR 1000 in electricity.

Thus far I've generated Bitcoins worth about EUR 1500 and my miners are hardly profitable anymore. If I'm lucky I'll make another EUR 500, and if I am very lucky (Bitcoin skyrockets) I'll barely break even.

The producer, Bitmain, obviously profited. Even more so did the government. More than 20% VAT means the government got EUR 400 at the customs. Electricity has more than 50% tax. For some reason people believe that electricity pollutes and that polluting is okay as long as you pay the government for it. In total the goverment has made around EUR 1000 on my mining business. Personally I'm in minus.

"Thank you" everyone who keeps investing in hardware. We lose. Our governments win.

Or maybe the upgrade is twofold:

1. Undervolt / underclock the existing boards.
2. Place secondary boards outside the existing ones. If you look at the S1 you'll see that these can easily be attached to the frame. These chips will need to use little electricity and have big heatsinks as they will not have any direct fans.

Since PSUs and S1 are dimensioned to 400W+ and it uses only ~100W after undervolting I believe it is doable with secondary boards as described. However, I'm afraid Bitmain will overprice these too such that there's nothing to gain.

EDIT:
Secondary boards may also be placed under or over the antminer such that these too are directly cooled by the fan's airflow.

Bitmain promised some time ago:


Has anyone heard anything about when it will be ready and how the kit's specs will be like?

+1 Excellent! Exactly what I wanted.

I wonder how much each miner has generated so far.

I know the hash rate of each miner and when I installed them, but I do not have statistics of how much each miner has generated. Is there any calculator that shows this based on historical data?

Anyone with a calculator and basic math skills know that mining is not profitable. Here are some reasons why:

1. It is rational to solo mine if you are risk seeking. A slight chance of making 25 BTC is worthwhile if you have an appetite for risk.

2. Manufacturers don't give away hardware. If for some time there is low demand, the manufacturers will rather mine in-house.

3. There are enough clueless mining enthusiasts to make a bubble. The pricing at CEX.io is a clear example of this.

4. Heat is a desired by-product. Some will naturally be willing to mine at a loss if the value of the heat is greater is than the loss.

5. Some don't pay for electricity.

6. Mining is fun. Some waste their money on booze and/or hookers. Others on mining hardware.

Other reasons?

A good calculator for mining:
https://bitcoinwisdom.com/bitcoin/calculator

Play with these inputs and you'll realize that it's almost impossible ever to break even.

I managed to make a profit of 0.65 BTC only by using some very strong assumptions:

Price = 0.75 BTC (I.e. no VAT/customs, free PSU)
Electricity only $0.10/kWh
Only 10% difficulty increment

It implies that no EU resident will ever be able to make a profit. If you live in some parts of the US, you might profit marginally, but not worthwhile given the risk of hardware failure.

May someone explain their rationale for investing in Antminer S3? Maybe something I missed?

Solo mining has reasonable odds.

The network hash rate is 120,000 TH. If you have 1 TH solo mining, then there's a 1/120,000 chance of finding the next block.

The probability of finding at least one block withing the next 13,000 blocks (three months) is:
1 - (119,999/120,000)^13,000 = 10.3%

Because of difficulty increases the probability is a bit lower, but it gives you an idea. There's around a ten percent chance you'll make 25 BTC on more solo mining within three months, and about 90 percent chance you'll make nothing.

I'd prefer the small pool option though. It has the best of both worlds, a small steady income with a few very lucky days.

Funny (or sad) thing is that professional investors who run gigantic farms will soon be out of business ... even at $0.05/kWh.
Lesson: Never underestimate the stupidity of the masses 

I wish there were a pool which rewarded the block finder with 12.5 BTC (the remaining 12.5+fees would de divided between all miners, just as a normal pool).

The total network hash rate is 120.000 TH, so even with just 1TH you play a game with reasonable odds.  Within the next 10,000 blocks (~2 months) you have an 8% chance of winning.

This would also help the network. Individuals would play for the same reason they participate in state lotteries. They are likely to "over-invest" (which they btw do all ready) so that the expected return turns negative. Large investors with data centers would be forced out.

OMG, 0.75 BTC ... how can you ever ROI with that price?
https://bitcoinwisdom.com/bitcoin/calculator

How can you defend the price of BTC 0.75 ?

I used https://bitcoinwisdom.com/bitcoin/calculator and it was impossible to reach ROI.

Dividends may even find a (perhaps unintended) use as address alias. Say I create a token called MYNAME. I issue only one share and keep it to myself.

Instead of handing out my bitcoin address, I tell people my asset name instead. It is easy to remember and to type in. To send me bitcoin you need to pay me a dividend. Right now that's too practical, but say that a wallet program automates this.

For example, in the "Pay to" field in Electrum you could insert either an address or a token name. Perhaps the token name could be of format [TOKEN]@XCP. This would truly make bitcoin the email of money.