Slashdot Mirror

I just checked a comparison of mining hardware and a mining profitability calculator. In essence, with the current prices ($120 last checked), GPUs are no longer profitable but a dedicated ASIC will pay itself back in less than a year even at $3/bitcoin.

Incidentally, I just realized how space based solar power could transfer the energy down to Earth. Just mine bitcoins in space, transfer them down and buy the electricity here.

Roadrunner consists of 6480 QS22 Blades. Using Cellminer each will yield approx. 56 MHash/s, or 363 GHash/s in total. Using the Bitcoin profitability calculator we can then estimate that one will gain ~27 BTC/day (ATM $2667) while paying $3360/day for power (assuming cheap $0.07/kWh). So yes: mining on Roadrunner would not be cost-effective.

The one thing that jumps out at me immediately is that, for almost any modern computer, a computer which is powered up but otherwise idle is going to draw less power than a computer which is mining bitcoins. If you want to use GPU mining (and, realistically, if you don't, this is probably a waste of time since you'll probably never mine any bitcoins) then I think you'll find the power draw from a mining machine is substantially higher than that of an idle machine.

So, what you need to do is work out your idle power consumption (with, say, a Kill-A-Watt meter), then work our your fully-loaded power consumption (preferably by trying to mine some bitcoins, but you could get a reasonable quick estimate by firing up a modern 3D game), work out the delta, which is your effective power consumption for mining, and then use one of the various calculators out there (e.g. http://www.bitcoinx.com/profit/) to decide if this is a profitable venture for you or not.

If you believe the mhash/s speeds of (yet to be released) ASIC hardware, as well as decentralized P2Pool mining, then you'll need to factor in the effect of disruptive technologies on "deflationary spirals". Bitcoin mining was something I was recently evaluating and decided against after researching and factoring in the effects of profitability decline per year on revenue, especially if ASIC hardware delivers as specced.

According to this profitability calculator with the current difficulty and market value, miners are now making a negative profit.

I know somebody that has a rig that does 1700 million hashes per second and uses 1000 watts (using 4 ATI 6970's). If you plug it into here, you'll find he nets an average of $1450.89 per month considering electricity at $0.15 per kwh

http://bitcoinx.com/profit/index.php

I decided against doing it myself because the miner growth rate is so high right now. It's around 5% a day, which means if it continues at the same rate, in 3 months it'll be more like $170 per month for his rig.

Here are some charts showing the growth rate: http://bitcoin.sipa.be/

I ran the numbers yesterday on using my 2 graphic cards and CPU to mine bitcoins and it just doesn't work out for me. To actually make money at it, I'd have to spec out a new system with the very newest graphic cards and use it just for mining... And it would still be quite a while before I saw a profit. And the market is always changing, and the difficulty to mine bitcoins is always increasing.

For anyone else interested, here's the site I used for the calculation: http://bitcoinx.com/profit/index.php

To give you an idea, my dual core 2.13ghz got about 1000 khashes/sec, my gt9600 got about 1800 khashes/sec, and my gtx550ti got about 38000 khashes/sec. (Yeah, that last one is a lot higher.) khashes are 1000 hashes, so that first number is actually 1 million hashes per second, but the calculator and most people talk in khashes instead.