Litecoin Mining on Mac OS X – G-Black ASICs

The first-generation Scrypt ASIC offerings continue to mature with larger and more powerful units being released regularly.

The GridSeed GC3355 chip saw its introduction on the single-chip DualMiner USB stick. The DualMiner was followed shortly by the 5-chip GridSeed Orb and then later the 80-chip GridSeed G-Blade unit.

In this article we’ll be taking a look at the next ASIC in the GridSeed family: the GridSeed G-Black.

GridSeed G-Black Open

The G-Black is a self-contained unit in a PC-style case with its own power supply. It is powered by 400 of the GC3355 ASIC chips from GridSeed. It is rated to draw 440W while providing 23 Mh/s performance.

While the majority of these GridSeed devices come to market with their own custom software, I continue working with several GridSeed vendors (and GridSeed themselves) to support these ASICs in BFGMiner. CGMiner no longer supports any algorithm or coin other than SHA-2 and Bitcoin, so BFGMiner was the natural choice here.

Miner Installation

As with the previous Scrypt ASICs, the G-Black is currently only supported on OS X by BFGMiner. So, the first step is to install BFGMiner. There is a thread here on the Bitcoin Talk forums which discusses various ways to install BFGMiner on Mac OS X. The most full-proof method is to use Homebrew:

  1. Launch Terminal.app from Spotlight or your Applications folder
  2. Install Homebrew by entering the following in the command prompt:
    ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go/install)"
  3. Run the following command and then fix any reported issues:
    brew doctor
  4. Tap the following Homebrew repository so that you can install packages from it:
    brew tap nwoolls/xgminer
  5. Finally, install BFGMiner:
    brew install bfgminer

Driver Installation

BFGMiner requires the correct kernel extension to be loaded in order to detect the GridSeed G-Black. When using BFGMiner the Apple Communication Device Class (CDC) driver will be used and should be automatically loaded by Mac OS X.

To load the required Apple drivers manually, execute the following commands:

sudo kextload -b com.apple.driver.AppleUSBCDC
sudo kextload -b com.apple.driver.AppleUSBCDCACMData

Detection

With the BFGMiner properly installed and the CDC driver installed, you can use the -d? argument to list available devices with BFGMiner:

bfgminer -d? -S noauto -S gridseed:all --scrypt
[2014-11-09 15:11:17] Started bfgminer 4.10.0-unknown
[2014-11-09 15:11:17] Devices detected:
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48E8646A3734; path=/dev/cu.usbmodemfd571)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48DD7F563734; path=/dev/cu.usbmodemfd511)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48E46F4C3734; path=/dev/cu.usbmodemfd5451)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48EE52493734; path=/dev/cu.usbmodemfd561)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48EC6F503734; path=/dev/cu.usbmodemfd5411)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48E358653432; path=/dev/cu.usbmodemfd5461)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48EC6F5B3734; path=/dev/cu.usbmodemfd5421)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48E481463734; path=/dev/cu.usbmodemfd531)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48E7745D3432; path=/dev/cu.usbmodemfd521)
[2014-11-09 15:11:17] STM32 Virtual COM Port by STMicroelectronics (driver=gridseed; procs=40; serial=48EA55583734; path=/dev/cu.usbmodemfd5471)
10 devices listed

Note the additional --scrypt argument since we will be Scrypt mining. I’ve also included the -S noauto argument to prevent GPU detection (for simplicity). Finally, note that a single G-Black shows up as ten individual devices as it is, in fact, ten units on five boards.

Mining

Once the GridSeed G-Black is detected you can start BFGMiner using the -o, -u and -p arguments to begin mining:

bfgminer -S noauto -S gridseed:all --scrypt -o hostname -u username -p password

BFGMiner G-Black

You can also over-clock the G-Black using BFGMiner and the --set argument.

bfgminer -S noauto -S gridseed:all --set gridseed:clock=835 --scrypt -o hostname -u username -p password

BFGMiner G-Black OC

The G-Black is yet another excellent performer from GridSeed that works great on OS X (as well as Windows and Linux in my testing).

If you have any questions feel free to post them in the comments below or on this thread at the Bitcoin Talk forums. And thanks to GridSeed for providing sample hardware. Happy Scrypt ASIC mining!

One thought on “Litecoin Mining on Mac OS X – G-Black ASICs

  1. Claude Davis

    Just picked up one of these G-Blacks. Excellent write up, and thank you for all the cool software you write. I’m running this machine off MultiMiner, and I downloaded the mobile version too. The fact that you have a mobile version for Win Phone is effin amazing =) I’m hoping to ask you some support questions for setting up an ideal coin/pool/argument strategy, or on your thoughts about multipool and conversion versus hold for speculation… Again, I appreciate your efforts. Great to be able to buy into brilliant people =)

    Reply

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