Java based Bitcoin miner

In my previous post on bitcoin mining using Mac OS X, I discussed what is in my opinion the easiest way to get your toes wet with mining: BitMinter. BitMinter is a great bitcoin mining pool and its Java based miner makes it very simple to try out bitcoin mining on Mac OS X using your graphics card to calculate hashes.

And while I’m a fan of the BitMinter pool, the mining software – though easy to try – has two notable downsides:

• The mining software only supports using BitMinter’s mining pool
• The performance of the mining software falls behind alternatives such as GUIMiner, cgminer and bfgminer

GUIMiner

In terms of ease-of-use, the next bitcoin miner for OS X I’ll discuss is GUIMiner. GUIMiner is also available for Windows and, unfortunately, it’s much easier to find recent binaries for Windows than for OS X.

You can download the official OS X release of GUIMiner here. However, this release is a year or so old at the time of this post. You may be able to find more recent releases here, but you’d be trusting unofficial code on your system.

After you download the disk image (dmg) file, make sure you move the guiminer.app file to a writable location. Attempting to launch it from the dmg file directly will result in GUIMiner crashing.

Once you launch GUIMiner, setup is straight-forward. You can click File>New to create a new tab for a miner. Only the OpenCL miner is supported out-of-the-box. After creating a new OpenCL miner tab, you can select a server (mining pool) from the drop down or select Other and enter the host, port, username and password manually. Select your device (graphics card) and finally click the Start mining! button.

If you have multiple graphics cards, you can add additional miners from the File>New menu or, if you plan on using the same mining pool, right-click your existing miner tab and click Duplicate.

As you can see there is a noticeable performance improvement using GUIMiner and the poclbm kernel instead of BitMinter. With my own hardware I get a boost of about 30 Mh/s using GUIMiner instead of the BitMinter client.

So GUIMiner works well on OS X, with performance benefits and the ability to taget any bitcoin mining pool. However, it does have a couple of drawbacks:

• The app doesn’t close properly – you must force quit the application
• The performance still isn’t comparable to native C miners such as cgminer and bfgminer

In the final post in this series I’ll discuss these last two miners: cgminer and bfgminer. These miners give the best performance that I’ve found. However, you’ll need to compile them yourself in order to use them, which isn’t a simple feat. There’s also some manual patching of C code required if you are running multiple graphics cards on OS X. Stay tuned!