[Update 4/30/2014: Prices have fallen, and I updated the article with current pricing. Also added a link to the YellowJacket USB miner. - Bryan]
The world of Bitcoin mining can be confusing if you're new. You used to be able to mine with your CPU, and then GPUs ruled the roost for a couple of years. Today, however, you'll need to buy specialized mining gear based on ASICs (application-specific integrated circuits), but the good news is that there are several entry-level options available, and you can run them from your Mac, a Windows PC, or a Linux box.
First, Where to Buy?
The most intimidating thing about Bitcoin mining is where to buy that gear. You can buy on Ebay, but I've found two U.S. retailers—JonesGear and ZoomHash.com—that not only offer excellent customer service, they back up the gear they sell.
I've bought several times from both retailers. I got one defective (manufacturer's defect) piece of gear from each company, and they both promptly replaced it. In the Wild West world of Bitcoin mining, that's worth a lot.
Better yet, both companies set up discount codes for you, my gentle reader, to use.
JonesGear: Use coupon code "MacObserver" during the month of April to get 5 percent off your order.
ZoomHash.com: Use coupon code "MacObserver" to get 7.5 percent off your order.
Return on Investment
The question that experienced/serious miners look at is what their return on investment (ROI) will be. In other words, if you spend $1,000 on mining equipment, how long will it take to generate $1,000 worth of Bitcoins—after you also pay for electricity.
Search for Bitcoin Mining Calculator, and you'll find a ton of them. I like the Bitcoin Mining and Profitability Calculator at VNBitcoin.org the best. No calculator tells the full story, though, because you can sell your used gear on Ebay or Craigslist when it still has value to someone coming up the Bitcoin ladder. Then, of course, you'll be free to buy new equipment of your own!
Another consideration is future value. If you think Bitcoins will rise in price, determining the value of Bitcoins mined today is massively subjective. My advice is to do your research and only invest in gear at levels you are comfy with.
Let's get to the gear! I started with the least expensive and worked my way up from there:
- Antminer U2 from JonesGear
- ASICminer Cube fro JonesGear
- Antminer S1 from JonesGear
- Gridseed Infinity 5-Chip from ZoomHash
Entry Level Mining Gear
Next: The Antminer U2
Behold the Antminer U2. It's literally a Bitcoin miner on a stick, a USB stick. This device hashes at 2 GH/s (giga-hashes per second), and it uses just 2 watts of power. They can be overclocked to 2.4 GH/s, too. As of this writing, they're just US$23 new from JonesGear (use coupon "MacObserver" for 5 percent off). If you want to dip your toes into Bitcoin mining just to see what it's all about, this is the device for you.
You can run them with CGminer and BFGminer on Windows and Linux. Mac users can use the command line version of either software, or MacMiner from Fabulous Panda, which puts puts a GUI on the command line apps. There's another GUI app called Asteroid you can use, too.
I love MacMiner.
The U2 has a fat heat sink on it, as shown in the picture, which means for most USB hubs, you'll only be able to use every other port. That would be an issue if you were planning on getting a lot of them, but I'm here to tell you not to get a lot of them.
At $11.50 per GH/s, they're expensive. Like I said, they're great for dipping your toes, but for a little more money, you can get a really cool device called the ASICminer Cube.
JonesGear also has the YellowJacket 2.2-3.0 GH/s USB ASIC Miner based on the Nanofury chip (a Bitfury chip, to be specific. I haven't tested this device, but it runs at 2.2 GH/s without overclocking, and JonesGear has it for $19. Use coupon "MacObserver" for 5 percent off.
Next: The ASICminer Cube
I love the Cube. It's a compact extruded-metal case that houses six blades that hold many Bitcoin mining ASICs on each one. With a fan on one end and a grilled opening on the other, it's easy to cool (see my tip below).
The Cube mines at 30 GH/s using some 200 watts of power, and as of this writing, they're priced at just $119 at JonesGear (plus 5 percent off when you use coupon "MacObserver"). It's also easy to overclock to 38 GH/s, though that bumps power consumption up to 280 watts.
ASICminer Cube - Front and back
Note that you need a separate PC power supply unit (PSU)—if you plan to run more than one Cube, get a PSU with the right number of connectors that supplies enough power for all of them.
Like I said, I love this device. It's stackable, it's well-built, and it only kind of looks like a piece of ugly mining gear. On the down side, it uses an early generation of ASIC, which is why it uses so much power. That ASIC also needs an older form of software that requires you to run Slush's proxy (you can also use BFGminer as a proxy in MacMiner).
I'll be writing up a tutorial on installing Slush's proxy on your Mac another time, but this is command-line world. The easiest thing would be to use BFGminer as a proxy, but when I tried that, I got less performance from the Cube.
Still, it's a good way to start mining for a relatively small investment.
Tip: The fan that the Cube comes with is NOISY. It's LOUD! If that's an issue for you, you can change out the fan, but do so at your own risk as it could void the warranty. I found that the excellent Scythe Gentle Typhoon keeps it cool at a tiny fraction of the noise. It adds to the price, but when you go to sell the Cube, put the old fan back on and keep the Scythe for your next miner.
Next: Step up to the Antminer S1
This is the best deal on the market today. For $379 at JonesGear as of this writing (plus a 5 percent discount when you use coupon the coupon code "MacObserver"), you get 180 GH/s of mining power using about 360 watts of power at the wall. That's more hashing power running much more efficiently than the Cube. [Price updated 4/14/2014]
If the price of electricity is no object for you, you can overclock this device to 200 GH/s—overclocking increases the hashing power by roughly 10 percent, but increases the watts per gigahash of power consumption by about 25 percent.
One of the best things about this device is that it includes its own mining software—really, it's own computer—that's built right into this thing. On a Mac, Windows PC, or Linux box, you simply configure it (add your mining pool, user name, and password) from a browser and let it do its thing. Your computer doesn't have to be turned on or even connected to it once you set it up, and that makes it much more user friendly than the Cube.
It also has built-in WiFi, but you'll need to get a third-party antenna to get any range out of it. Doing so means you won't have to connect it to your network via ethernet.
If you're willing to invest US$379 (after the coupon) in mining gear, this is the way to start. It's the best price per GH/s at the entry level—roughly $2.10 per GH/s—running on the least power.
On the down side, this thing is essentially two motherboards bolted to a frame. It's open to the air, and uses a loud fan to keep it cool. if you don't admire the elegant beauty of minimalist electronics, it's unattractive and will need to be placed in a suitable place.
Tip: There are ALL kinds of cooling mods that engineers and people nerdier than me have come up with, but I found that replacing the main fan with a Corsair SP120 and adding a Scythe Gentle Typhoon on the other end of the S1 to pull air out keeps it cool with little noise.
Next: The Curious (and Cool) Gridseed Infinity
My last piece of entry-level gear to mention is the Gridseed Infinity (also called the Gridseed 5-chip), which I buy from ZoomHash for $134.99. This is a curious device—it not only looks funny (it reminds me of a funky oil filter), it lets you mine Bitcoins or Litecoins (or any Scrypt-based coin), and if you want to live life on the wild side, you can mine both AT THE SAME TIME!
The Gridseed Infinity - Top and Bottom
It has three modes:
- Scrypt mining: ~350 KH/s @ 7W
- SHA-256 mining: ~11.25 GH/s @ 60W
- Dual Scrypt and SHA-256 mining: ~200 KH/s Scrypt & ~8 GH/s SHA @ 60W
Scrypt mining is a different beast than Bitcoin mining, which is based on SHA-256 encryption. In fact, there is no comparison when it comes to hashing rates, and 350 KH/s is much more powerful than it seems when compared to all the numbers associated with Bitcoin mining.
What's cool is that you can get Bitcoins with Scrypt mining if you mine with a multi-pool like ScryptGuild (my favorite). The pool mines a variety of Scrypt coins, automatically choosing the most profitable coin as it goes, and then you can have your Scrypt coins automagically converted to Bitcoins. As of this writing, one Gridseed Infinity will earn about 0.0015BTC per day using this method. Your mileage will vary.
Tip: If you have a powerful videocard made by ATI (which is owned by AMD) in your iMac or Mac Pro, Scrypt mining with your GPU could be profitable. In fact, almost all Scrypt mining is still done with GPUs, and that's likely to be the case for the next several months or so. Just be aware that it puts wear and tear on your video card to run full tilt all the time.
The reason I like to Scrypt mine (single mode) with the Gridseed Infinity is power consumption. You can earn a little more if you dual mine with this thing, but it uses so much less power if you're just Scrypt mining—7 watts vs. 60 watts! Your GPU will use far, far more power than that doing any kind of mining.
Plus—and this will most likely void your warranty—you can desolder the fan and run it fanless in Scrypt-only mode. That makes it silent, and silent is SO MUCH QUIETER! There are also a bunch of super nerdy engineering things you can do to tweak performance and get as much as 500 KH/s of hashing power out of it (they all void your warrant, but it's so cool!).
There's one more thing: the Gridseed Infinity is less Mac friendly. The easiest way to run these with a Mac is to get the Controller that Gridseed makes that you configure with a browser, just like the Antminer S1.
The developer behind MacMiner has been working his butt off to support this thing, but many people have had to turn to Linux or Windows to run it. If you don't get the controller, you need to have your nerd chops up to date to play with this thing.
I have personally run it with Ubuntu in a Parallels installation on a Mac, but more recently I got a Raspberry Pi to run four of them. It requires some command line know-how, but it (again) uses very little power. There are many setup guides available, no matter which way you want to set it up.
The Gridseed Infinity is $134.99 at ZoomHash.com as of this writing, but using coupon code "MacObserver" will shave 7.5 percent off your order. [Price updated 4/30/2014] Add a preconfigured Raspberry Pi for $74.99, and the coupon applies to that, too.