So is BitCoin Mining it really worth doing at home?
The short answer for me and for most people is: No.
I’m sure there are ways to make it profitable, but after a short experiment I determined that the electricity cost of running the tools to mine BTC is usually much more expensive than the potential gain you will receive. Unless you don’t pay for your own electricity, then I suppose its worth it at the cost of someone else.
Pooled vs. Solo Mining:
Pooled mining is the only way that an individual really has a chance at generating an income from mining BTC. It favors much smaller but more regular gains. With pooled mining, you basically split the gains of a block discovery amongst the contributors in the pool.
You can “go it alone” and set up your own solo BTC mining server, but the chance of a discovery on your own is extremely rare. i.e. a single block discovery would take on average a number of years. The cost recovery on a single block discovery is currently about 25 BTC and at current rates 1 BTC = ~$13.5 USD in trade… so a whole $337 for many years of running your equipment hot. Not an option unless you really plan out your mining solution and keep in mind you are competing against very very large compute pools for a block discovery. So this is not really an option for people with just a few machines at home trying to generate a small income.
What all this stuff means:
BitCoin is a currency. It’s fairly straight forward to understand that concept, but what does mining, block discovery and all this stuff have to do with it? I’ll try and explain without going into too much technical details.
As far as I understand it, BitCoin basically needs a constant stream of new encrypted blocks to support it’s economy and stay alive. Each block is generated using a determined value from the preceding block and contains a value that will be used in calculations for the next block. New blocks are generated through BitCoin Mining.
BTC Mining basically uses your compute resources to run through hash values to try and discover the next valid block in the chain based on the previous and next block requirements. These discovered valid blocks are validated by the connected community and then the award (currently 25 BTC) is handed out to the person or pool that made the discovery. This is how BTC Mining generates income.
These hash values are usually calculated on current hardware in the Mh/s or Millions of Hashes per Second.
On my machines, I was able to get anywhere from 800Kh/s using a CPU based miner software up to just over 100Mh/s using the GPU on my main desktop PC.
Ok, so how much BTC mining do I have to do to make some real money?
I ran my tests using one of the more popular BTC Mining sites. This site wins discoveries on about 13% of all new blocks and the winnings are split fairly among the pool contributors with a 2% fee. This pool is very large (over 2500Gh/s overall), so the payouts are pretty small on an individual basis.
Using BTC software that is freely available all over the place, I was able to get 4 machines at home up and running on the pool.
1. A Dual Core 3.0Ghz Windows 2008 Server – CPU mining at ~845Kh/s
2. A Laptop with an nVidia 4200M GPU – GPU mining at ~10.1Mh/s
3. A Secondary Desktop with nVidia GTX 285 – GPU mining at ~59Mh/s
4. My Main Desktop with nVidia GTX 470 – GPU mining at 103Mh/s
At any given time, I was averaging about 150Mh/s at the mining pool site.
I ran this for about a 24hr period to see how much BTC I would generate. The result was a little over 0.03 BTC. Given that rate, it would take me over a month to generate a single BTC for ~$13.5USD….
Ok, so how much electricity does this cost to run?
Using a cheap energy meter I bought for about $10 at Home Depot or Canadian Tire a number of years ago, I was able to measure the actual Watt usage of all my machines at Idle and at Load while running the mining application at full speed.
I didn’t bother with the CPU miner, as it’s obvious that it can’t sustain enough h/s to be of use, so I focused on the other machines with GPUs. The Watts shown here are above what the machine takes at idle, so it’s a pure cost of mining assuming i leave my machines on at idle 24/7 (which I’m bad, and I do).
1. Laptop – 10.1Mh/s – 7 Watts
2. Second PC – 59Mh/s – 187 Watts
3. Main PC – 103Mh/s – 141 Watts
The Laptop is actually the best H/s per Watt performer, but 10Mh/s doesn’t get you much in the long run.
My electricity rates go from $0.068/kWh off peak times to $0.118/kWh at peak times. I’ll cut the difference and use $0.093/kWh as a rough estimate. Again, this is just the cost in the increased load of mining.
1. Laptop – 0.168 kWh/day, $0.47/mo
2. Second PC – 4.488 kWh/day, $12.70/mo
3. Laptop – 3.384 kWh/day, $9.57/mo
BTC income:
1. Laptop – 0.0612 BTC/mo, ~$0.81 USD
2. Second PC – 0.3613 BTC/mo, ~$4.77 USD
3. Main PC – 0.6307 BTC/mo, ~$8.33 USD
Wait a minute….
Ok, cost of electricity vs potential income makes this effort not worth it at all … that, plus the extra stress on the GPUs results in greatly shortening the life of the graphics cards.
1. Laptop – net +$0.33/mo
2. Second PC – net -$7.93/mo
3. Main PC – net -$1.25/mo
With the current hardware that I have, only the laptop is capable of generating enough h/s to actually overcome it’s energy requirements.
There has to be a way to make this work….
The easy answer is “yes, there is”, but you need to create a special rig for mining where the energy requirement is outweighed by the number of h/s to make it worth it.
There are graphics cards on the market today that can increase your output per watt far greater than what I was able to achieve (up to 650Mh/s per 350W)… but you then have the added cost of purchasing those graphics cards… and at $200-400+ per card, you wouldn’t recover your initial costs for quite some time.
There is also the risk of BTC payouts becoming less and less over time diminishing the return on the investment. Every 210,000 blocks that are generated, the discovery payout is reduced by half. So eventually the payouts will be halved again and again over time. New blocks aren’t generated that often (about 1 every 10mins), but this is something to consider if you are investing time or money.
All in all, its not really worth it to generate BTC at home as a hobby. The investment you would need to make to generate any serious dollars (even enough to break even on your Hydro bill and initial cost of hardware) is a lot more than most people can afford for an at home project. Combine the risk involved with lower payout over time, it’s really not worth the effort.
-Paul
