Does it mean I can generate free Bitcoin from my computer?

Is it still profitable to mine Bitcoin these days?

Well, stick around...

Here on Bitcoin Whiteboard Tuesday,

we'll answer these questions and more.

Bitcoin was created as a decentralized alternative

to the banking system.

This means that the system can operate and transfer funds

from one account to the other

without any central authority.

With a central authority,

transfering money is easy:

Just tell the bank you want to remove $50 from your account

and add it to someone else's account.

In this case,

the bank has all the power,

since the bank is the only one who is allowed to update the ledger

that holds the balances of everyone in the system.

But how do you create a system that has a decentralized ledger?

How do you give someone the ability to update the ledger

without giving them so much power

that they will become corrupt or negligent in their work?

Well the rules of the Bitcoin system, known as the protocol

solves this in a very creative way I like to call

“Who Wants to Be a Banker?”

In short,

anyone who wants to participate in updating the ledger of Bitcoin transactions,

known as the blockchain, can do so.

All you need to do is

guess a random number that solves an equation generated by the system.

Sounds simple, right?

Of course this guessing is all done by your computer.

The more powerful of a computer you have,

the more guesses you can make per second,

thus increasing your chances of winning this game.

If you managed to guess right -

you earn Bitcoins and get to write the “next page” of Bitcoin transactions

on the blockchain.

Here's a more detailed breakdown of the mining process:

Once your mining computer comes up with the right guess,

your mining program determines which of the currently pending transactions

will be grouped together into the next block of transactions.

Compiling this block represents your moment of glory

as you have now become the temporary banker of Bitcoin

who gets to update the Bitcoin transaction ledger

known as the blockchain.

The block you've created, along with your solution

is sent to the whole network so other computers can validate it.

Each computer that validates your solution

updates its copy of the Bitcoin transaction ledger

with the transactions that you chose to include in the next block.

As you can imagine,

since mining is based on a form of guessing;

for each block, a different miner will guess the number

and be granted the right to update the blockchain.

Of course the miners with more computing power

will succeed more often,

but due to the laws of statistical probability,

it is highly unlikely that the same miner will do so every time.

After this stage is complete,

the system generates a fixed amount of Bitcoins

and rewards them to you

as a compensation for the time and energy you spent in solving the math problem.

Additionally, you get paid any transaction fees

that were attached to the transactions you inserted into this block.

So that's Bitcoin mining in a nutshell.

It's called mining because of the fact

that this process helps “mine” new Bitcoins from the system.

But if you think about it, the mining part is just a by product of

the transaction verification process.

So the name is a bit misleading,

since the main goal of mining is to maintain the ledger

in a decentralized manner.

Now that you know what Bitcoin mining is

you might be thinking “cool! Free money!

So where do I sign up?” Well, not so fast….

Satoshi Nakamoto, who invented Bitcoin,

crafted the rules for mining in a way that the more mining power the network has,

the harder it is to guess the answer to the mining math problem.

So the difficulty of the mining process

is actually self adjusting to the accumulated mining power

the network possesses.

If more miners join, it will get harder to solve the problem;

If many of them drop off, it will get easier.

And this is known as the mining difficulty.

So why on earth did Satoshi do this?

Well, he wanted to create a steady flow of new Bitcoins

to the system.

In a sense, this was done to keep inflation in check.

The mining difficulty is set so that on average

a new block will be added every 10 minutes.

Now remember, this is on average.

We can have two blocks being added minute after minute

and then wait an hour for the next block.

In the long run this will even out to 10 minutes on average.

As you can imagine,

this type of self adjusting mechanism created some sort of an “arms race”

to get the most efficient and powerful miners

as soon as possible.

When Bitcoin first started out there weren't a lot of miners out there.

In fact, Satoshi, the inventor of Bitcoin,

and his friend Hal Finney were some of the few people

mining Bitcoin back at the time with their own personal computer.

Using your CPU,

meaning your Central Processing Unit or your computer's brain,

was enough for mining Bitcoin back in 2009 since the mining difficulty was low.

As Bitcoin started to catch on

people looked for more powerful mining solutions.

Gradually people moved to GPU mining.

A GPU or Graphics Processing Unit

is a special component added to computers to carry out more complex calculations.

GPUs were originally intended to

allow gamers to run computer games with intense graphics requirements.

Because of their architecture

they became popular in the field of cryptography

and around 2011 people also started using them to mine Bitcoins.

For reference, the mining power of one GPU equals that of around 30 CPUs.

Another evolution came later on with FPGA mining.

FPGA is a piece of hardware that can be connected to a computer

in order to run a set of calculations.

They are just like a GPU, but 3 to 100 times faster.

The downside is that they are harder to configure,

which is why they weren't as commonly used in mining as GPUs.

Finally, around 2013 a new breed of miner was introduced -

the ASIC miner.

ASIC stands for Application Specific Integrated Circuit,

and these were pieces of hardware

manufactured solely for the purpose of mining Bitcoin.

Unlike GPUs, CPUs and FPGAs they couldn't be used to do anything else.

Their function was hardcoded into the machines.

ASIC miners are the current mining standard.

Some early ASIC miners even appeared in the form of a USB

but they became obsolete rather quickly.

Even though they started out in 2013

the technology quickly evolved

and new more powerful miners were coming out every 6 months.

After about 3 years of this crazy tech race

we've finally reach a technological barrier and things have cooled down a bit.

Since 2016 the pace at which new miners are released has slowed considerably.

Now that you know what miners are,

let's talk a bit about mining pools.

Assuming you're just entering the Bitcoin mining game,

you're up against some heavy competition.

Even if you buy the best possible miner out there

you are still at a huge disadvantage

compared to professional Bitcoin mining farms.

That's why mining pools came to existence.

The idea is simple -

miners group together to form a “pool”.

Meaning they combine their mining power to compete more effectively.

If the pool manages to win the competition,

the reward is spread out between the pool members

depending on how much mining power each of them contributed.

This way even small miners can join the mining game

and have a chance of earning Bitcoin,

even though they get only a part of the reward.

Today there are over a dozen large pools

that compete for the chance to mine Bitcoin and update the ledger.

I know you might be thinking,

“ok, all this theory stuff is very nice,

but is Bitcoin mining actually profitable today?”

Well, the short answer is “probably not”,

the correct (and long) answer is “it depends on a lot of factors”.

When calculating Bitcoin mining profitability

there are a lot of things you need to take into account.

Let's go over them quickly

A Hash is the mathematical problem the miner's computer needs to solve.

The Hash Rate refers to your miner's performance

or how many guesses your computer can make per second.

Hash rate can be measured in Mega hash per second (MH/s),

Giga hash per second (GH/s),

Terra hash per second (TH/s)

and even Peta hash per second (PH/s).

This refers to the number of Bitcoins generated

when a miner finds the solution.

This number started at 50 Bitcoins back in 2009

and is halved every 210,000 blocks, about four years.

The current number of Bitcoins awarded per block is 12.5.

The last block halving occurred in July of 2016

and the next one will be in 2020.

This is a number that represents how hard it is to mine Bitcoins

at a certain moment

according to the amount of mining power currently active in the system.

How many dollars are you paying per KiloWatt.

You'll need to find out your electricity rate

in order to calculate profitability.

This can usually be found on your monthly electricity bill.

The reason this is important is because miners consume electricity -

whether for powering up the miner or for cooling it down

as these machines can get really hot.

Each miner consumes a different amount of energy.

You'll need to find out the exact power consumption of your miner

before calculating profitability.

This can be found easily with a quick search on the Internet

or through this list.

Power consumption is measured in Watts.

If you're mining through a mining pool, and you should,

then the pool will take a certain percentage of your earnings

for rendering their service.

Since no one knows what Bitcoin's price will be in the future

it's hard to predict if Bitcoin mining will be profitable.

If you are planning to convert your mined Bitcoins in the future

to any other currency,

this variable will have significant impact on your profitability.

And finally #8 - The Difficulty increase per year -

This is probably the most important and elusive variable of them all.

The idea is that since no one can actually predict

the rate of miners joining the network,

neither can anyone predict how difficult it will be to mine

in 6 weeks, 6 months or 6 years from now.

In fact, in all the time Bitcoin has existed

profitability has dropped only a handful of times,

even at times when the price was relatively low.

The last two factors are the reason

that no one will ever be able to give a complete answer to the question

"is Bitcoin mining profitable?"

Once you have all of these variables at hand

you can insert them into a Bitcoin mining calculator

and get an estimate of how much Bitcoin you will earn each month.

If you can't get a positive result on the calculator

it probably means you don't have

the right conditions for mining to be profitable.

I assume by now you pretty much know if mining is for you or not.

But you may have also heard about other types of mining

like cloud mining, mobile mining or even web mining.

Cloud mining means that you do not buy a physical mining rig

but rather rent computing power from a mining company

and get paid according to how much mining power you own.

At first this sounds like a really good idea,

since you don't have to go through all of the hassle of

buying expensive equipment, storing it, cooling it, and monitoring it.

However, when you do the math

it seems that none of these cloud mining sites are profitable.