It's not without controversy, however. Bitcoin was the currency of choice at former Internet drug bazaar Silk Road and remains the currency of choice of crypto locker hackers that hold people's computers hostage for money. But don't let that discourage you.
When I first researched Bitcoin (at the end of 2012) the price of a single Bitcoin was $13.50. In May 2013 it was selling for around $200/BTC. When I finally got around to buying some Bitcoin (on November 10) it had jumped to $460/BTC, and as I write this on November 26 the price has skyrocketed to $920/BTC. Not too shabby.
But enough on the background of Bitcoin, there's plenty of places to read about that. Let's get down to business and how to mine Bitcoin using your Mac.
First, some bad news. While it's technically possible to mine for BTC using your Mac's GPU, it's not profitable. The hashing difficulty has increased to a point where you'll spend more on electricity than you'll get in Bitcoin in return. It's possible that the new Mac Pro (with it's dual AMD FirePro GPUs) might be able to mine for Bitcoin profitably, no one's benchmarked its hashing performance yet.
The good news is that you can purchase purpose-built mining hardware that will mine Bitcoin. While potentially profitable, there are several caveats. ASIC mining hardware is backordered, expensive, power hungry and loud. I backordered a 5Gh/s and a 25Gh/s ASIC (both pictured above) from ButterFly Labs in May and just got them this month, a six month backorder. If you're serious about getting into Bitcoin mining I suggest that you either purchase a BFL miner on eBay, or place a pre-order for one of the rip-snortin' fast 300 or 600Gh/s miners that Butterfly Labs will begin shipping in January.
If I haven't scared you off and you're still reading, here's what you need to do to begin mining for Bitcoin on your Mac.
Step 1. Create a wallet
Create a Bitcoin wallet at BlockChain.info and note your Bitcoin address. You'll need it in step 2. A wallet is used to store your Bitcoin and you can have as many wallets as you want. Remember that security is paramount and losing your credentials is akin to losing your physical wallet, except that no one's going to return it to you. Also, if you lose your credentials, your Bitcoin is gone forever, there's no way to recover your password. There are many options for online and offline wallets and an offline wallets are more secure, but if you're starting at zero an online wallet is fine for the time being. (If you plan on purchasing Bitcoin with real money, then I recommend that you educate yourself on the risks and store your Bitcoin in an offline wallet that is backed up.)
Step 2. Join a pool
Join a mining pool, like BitcoinCZ Mining (aka Slush's pool). Bitcoin pooled mining is a way for multiple users to work together to mine Bitcoin, and to share the benefits fairly. Create and record logins and passwords for as many workers as you need. If you purchased ASIC hardware to run on one Mac, one worker is sufficient. If you want use a bunch of computers in your home or office to mine, then create a worker account for each machine that you plan to enlist.
Step 3. Install the mining software
There aren't a lot of Bitcoin mining clients for the Mac and if you uncomfortable with the command line/Terminal (or would just like a little more feedback) I recommend a free OS X mining client called MacMiner. Download it, install it and configure it to send rewards to your BlockChain wallet and to work in the pool that you joined. Here's how.
Step 4. Connect your ASIC miner to your Mac's USB port.
Step 5. Configure Mac Miner's Pool Settings
Open the FPGA/ASIC Miner window (from the View menu).
Click on "Pool Settings" in the upper-left of the FPGA/ASIC Miner window.
Enter your BTC address for rewards (from your wallet in Step 1)
In the BTC area (bottom left) select your mining pool from the drop down menu
Enter your miner username and password from your mining pool (Step 2 above)
Click "Save & start"
Step 6. Configure Mac Miner's Miner Settings
Click on "Miner Settings" in the FPGA/ASIC Miner window
Enter "-S all" (without the quotes, capital "P") in the Devices/manual flags field
Step 7. Click Start
In the FPGA/ASIC Miner window (in Step 5 above).
Step 8. Watch the Bitcoin roll in
To monitor your progress, log into your mining pool account and watch the "My Account" page. I have Slush's Pool set to transfer my BTC rewards to my wallet every 0.1 BTC (the "Send threshold" below) and as you can see by the screenshots, I've been getting 35-36Gh/s hashing performance from my two BFL miners pictured above. At 36Gh/s I've been able to mine 0.1 BTC every four days and I'm on a pace to mine 1BTC/40 days at the current difficulty level.
The next generation of mining hardware from Butterfly Labs are a pair of PCI cards based filled with 28nm ASICs that are capable of mining at 300Gh/s ($2,800) and 600Gh/s ($4,680) respectively. Orders places today for the new "Monarch" cards are expected to begin shipping in February 2014. KnCMiner, based in of Stockholm Sweden, is taking pre-orders for a 3 Terahash miner called Neptune, only 1200 units are being made and one will set you back $12,995. According to the founders, Neptune can mine 2.1 Bitcoin per day at current difficulty levels.
Update 2013-1203: I've switched from using MacMiner to Asteroid, a new Bitcoin mining client for Mac. More on Asteroid in a future blog post.
Q: Can I set up MacMiner on a bunch of computers and mine BTC that way? (ala SETI@home)
A: While you can, it's not economically feasible with the current level of hashing difficulty and the cost of electricity.
Q: Where can I buy Bitcoin?
A: If you're in the U.S., you can buy BTC at Coinbase.com. They're US-based and raised $5M in venture capital in May 2013 (WSJ article)
Q: Where can I purchase ASIC mining hardware?
A: I purchased two minging rigs (pictured above) from Butterfly Labs and they rock -- to the tune of 36Gh. Note: BFL is running a Black Friday Special with 25 percent off mining hardware Friday only (in your local time zone). Minr.info maintains a list of currently discussed ASIC bitcoin mining hardware.
Q: Where can I follow what's happening in the Bitcoin community?