Bitcoin Forum

I stumbled upon an article on Bitcoin today, and did some calculations.

Apparently, each Bitcoin is worth 17.5$.

Mining for Bitcoins is done in Mhash/s, and every 46 are worth 1$,

Which means that 800 Mhash/s (for one day) are worth 1 Bitcoin (or 17.5$).

As an example, an HD 6990 manages just around 800 Mhash/s, with a 400w peak power consumption.

Now the price of electricity ranges from 6 cents for a Kw/h to 18 cents, so let's take a median-high - 15 cents.

That's 400w x 24 = 9,600w / 1,000 = 9.6Kw/h x 15 cents = 144 cents = 1.44$.

Which equates to a Profit of 17.5$ - 1.5$ = 16$ per day, or 112$ per week, or 450$ per month.

Now you can scale that essentially up to any number (I assume).

Say you own two rigs with 8 HD 6990s, considering that the rest of the components run at idle.

That's 8 x 900 (overclocked) = 7,200 Mhash/s, with a typical power consumption of 2,400w-3,200w (let's say 2,800w).

That's 2800w x 24 = 67,200w / 1,000 = 67.2Kw/h x 15 cents = 1008 cents = 10$.

Now for the profit. 7,200 Mhash/s / 800 = 9 Bitcoins = 157.5$ - 10$ = 147.5$, or 1,032$ per week, or 4,130$ per month, and 50,000$ per year.

So now I'm going to wait for someone to poke a hole in my plan to make 50,000$ a year without doing any more work than simple maintenance and upkeep, minus original funds for purchasing the components.

Again, this is just something I found interesting as I love calculations :)

800 Mhashes gets you about .6 BTC per day at the current difficulty.


Try this calculator www.kaptain.me/btc_calc.php (http://www.kaptain.me/btc_calc.php)

Your information is a bit outdated. With the difficulty change that hit a few days ago, Bitcoin/day are nearly halved. At the moment, my 850MHash/s running for a day is ~.62 bitcoin.

You also didn't take in consideration for hardware costs, which is quite a sum. Even though the numbers look really nice, they're rather misleading, especially when they don't take the difficulty increases over time in consideration.

So, now it's 40% less than before?

How much lower is it going to get?

I was under the impression that there was a static amount of bitcoins.

EDIT: This is crazy! In a week, it will be worth 50% as much as my original calculations..

I mean, it's still over 2,000$ a months from essentially doing nothing, but still.. why this decline?

There is a set number of bitcoins, but there is also a system that limits how many bitcoins/hour are given out (difficulty). The more miners there are online, the harder it gets to generate bitcoins. https://en.bitcoin.it/wiki/Difficulty (https://en.bitcoin.it/wiki/Difficulty)

And why is this? Because hardware keeps getting more powerful?

If so, that would still work well, since you could buy a new graphics card when it's released, then sell it for 75% of its original price when its successor comes out, and have little down time.

Anyone think it's still worth it?

I want to see someone who's actually doing what I plan on doing, with at least 8 GPUs.

Keep reading. Some of that first stuff makes no sense and the difficulty will keep increasing until it is right on (or past) the edge of profitability.

You really think it will increase so rapidly, that even with GPUs doubling in performance every 12 months, we still couldn't turn a profit?

I mean, heck, even with twice the revenue to overhead, it's still worth it on some scale.

Difficulty is doing much more damage to your plans as you think.

Look at this chart from http://forum.bitcoin.org/?topic=2345.0 (http://forum.bitcoin.org/?topic=2345.0)

http://commondatastorage.googleapis.com/bitcoin/difficulty-by-time.png

Here is a more detailed chart of difficulty increases from http://bitcoin.sipa.be/speed-lin-10k.png (http://bitcoin.sipa.be/speed-lin-10k.png)

Your profit projections must make some allowance for difficulty increases.

http://bitcoin.sipa.be/speed-lin-10k.png

You have to consider the selling price. It's not USD17.50 now; it's more like $16.++ now (that is if there's a bitcoin buyer for your bitcoins). On the other hand, the cost of electricity is constant ... per your calculation, USD40++ / mo. And that's just for the system running. You'll have to take into account the cost to keep the air / room temperature down during the current summer months or maybe add a fan blowing at the system. Otherwise the heat could kill your cards. Then it's more hardware costs.

lol ... never mind. I'm just being pessimist and amazed at the miner's. How do they break even?

Everyone buying and mining at the moment is speculating that bitcoins are going to be worth a lot more in the future.