The media is buzzing these days with stories about bitcoin, the most popular of available crypto currencies. First proposed in 2008 and implemented in 2009, recent bubbles and crashes in the exchange-rate for the bitcoin have everyone talking about it. And while the volatility and investment possibilities of bitcoin are intriguing, to me the truly interesting aspect is the role of the bitcoin miner.
As the name implies, bitcoin miners – which are generally either computers or specialized hardware – are responsible for mining new bitcoins. However, that is not their primary function. Those individuals running bitcoin mining software are, in effect, running the bitcoin transaction processing network in a peer-to-peer fashion. You can think of this as another distributed computing system like SETI@home and Folding@home. By using your computer hardware’s spare cycles you can contribute to a growing, global, distributed crypto currency. If that’s your thing.
And you can actually come out ahead financially. Now, arguably, this won’t last much longer. There is specialized hardware on the horizon that may make it much less profitable to mine bitcoins. But, for the time being, if you already have a Radeon 5x series or higher GPU then there’s a decent chance you could do this and make a couple of dollars a day (US, not bitcoin). Check out this hardware chart and this calculator for more information.
As it happens the most recent Mac Pros ship with Radeon 5x series GPU’s and can use 6x series Radeons with OS X Lion. However, most of the bitcoin mining software is aimed at Windows and Linux. There really aren’t a lot of options available for mining bitcoins on OS X without a little extra effort.
In this series of articles I’ll talk about three options for bitcoin mining on OS X:
- BitMinter – a Java app that uses OpenCL for mining
- GUIMiner – a GUI wrapper for a Python OpenCL miner
- cgminer & bfgminer – native command-line utilities that use OpenCL to mine
BitMinter is a great service for trying out bitcoin mining with minimal effort. BitMinter functions as a bitcoin pool and as mining software. Their mining software is a Java app. While Java can be a good choice for providing a single app for multiple platforms, recent changes in the Java runtime environment on OS X mean that the BitMinter app may not run without some work.
If you are running the latest version of Mac OS X and attempt to launch the BitMinter Java app, the odds are you’ll be faced with this dialog:
If that is the case, simply click on this knowledgebase link from Apple and follow the instructions. Afterward you should be able to launch the .jnlp files by double-clicking them. If you are still having trouble, launch them from the command line with the javaws utility:
Once the BitMinter app fires up, you’ll see collapsable panes for each CPU and GPU. It is absolutely not worth mining bitcoins on your CPU at this point (though you could look into Litecoins to put your CPU to work). To start mining, click the Engine Start button for each of your GPU’s.
And you are now off and mining. You should see a Mh/s readout in the status bar. This is the number of hashes per second your hardware is performing. And, while the BitMinter miner is one of the easiest to try on OS X, it is worth noting a few downsides:
- Your performance will be much better with native command-line miners such as cgminer or bfgminer
- You are forced to use BitMinter as your mining pool when using the BitMinter miner
So far I’ve glossed over the idea of mining “pools”. While this is outside the scope of this article, know that you will need to pick a pool to participate in. Mining pools are collections of individuals mining common blocks of bitcoin transactions. This means you get paid small fractions every couple of hours instead of waiting months or even years for larger, rounder payouts. They have different payout methods and percentages, but BitMinter is a very good one with low fees (1% currently). You can read more about the available bitcoin pools here.
If you’ve tried out mining with BitMinter and it seems interesting to you, watch for future articles on using GUIMiner, cgminer and bfgminer on OS X. These utilities remove the Java requirement and offer performance improvements while also letting you participate in the pool of your choice.