Custom build mining rig

Custom build mining rig

One of my spare time projects I’m recently into is mining altcoins for fun. As most of these projects start small, in my case a single GPU in a desktop PC. Which ended up with an open rig containing four GPU’s. I tried to build a rig that would run stable and energy efficient as possible.


I decided to go with the AMD Radeon 7950 cards, they are claimed to be one of the most efficient cards to mine scrypt coins with a high hash per watt ratio. The components below are selected with running a headless Linux server in mind.

  • Mainboard: ASRock H77 Pro4-M (socket 1155)
  • CPU: Intel Celeron G1620
  • Memory: Kingston 4 GB DDR3-1600
  • GPU: 4x Asus HD7950-DC2T-3GD5-V2
  • Storage: Kingston DataTraveler Ultimate 3.0 Gen2 32GB (USB flash drive)
  • PSU: Corsair AX1200i
  • Additional: 4x powered PCIe Riser Cable Extension 1x to 16x

There were a few issues that a raised after adding the  second GPU. I had to change the BIOS parameter ‘Active Processor Cores’ to 1 because of a soft interrupt issue. I also disabled all audio options in the BIOS and be sure ‘Primary Graphics Adapter’ is set to ‘PCI Express’.


For this system I have created a bootable Linux USB flash drive. Have a look at this post.

I started mining Litecoin, which is based on the Scrypt algorithm. Therefore I used cgminer 3.7.2, the last version which supports GPU and Scrypt mining. Recently I switched to mining BlackCoin on the BlackCoin Pool, were it’s possible to mine using the X11 algorithm. X11 uses close to 50% less energy and produces less heat, so this is really handy as summer is approaching. To use X11 I had to install sph-sgminer 4.1.0 from github.

It took some time to have the cards run with optimal (overclocked and undervolted) settings. Currently the following is active:

"failover-only" : true, "no-pool-disable" : true, "auto-fan" : true, "intensity" : "19,19,19,19", "worksize" : "256,256,256,256", "kernel" : "darkcoin,darkcoin,darkcoin,darkcoin", "lookup-gap" : "2,2,2,2", "gpu-engine" : "0-1060,0-1060,0-1060,0-1060", "gpu-memclock" : "1600,1600,1600,1600", "gpu-vddc" : "1.075,1.075,1.075,1.075", "gpu-fan" : "40-95,40-95,40-95,40-95", "temp-cutoff" : "85,85,85,85", "temp-overheat" : "75,75,75,75", "temp-target" : "55,55,55,55", "expiry" : "120", "gpu-threads" : "1", "gpu-powertune" : "20,20,20,20", "queue" : "1", "scan-time" : "30", "scrypt" : true

Happy mining!