About one year ago began the frantic race to begin acquiring motherboards, power supplies and GPUs for the purpose of mining which was fairly profitable at the time. Specifically, mining operators were scrambling to source the higher-end GPU hardware necessary to add capacity as it was becoming apparent that the rate of the difficulty rises was probably not going to be slowing.
The typical high-end rig of the day was a dual ATI HD 5970 rig costing $1,500 and capable of hashing at 1.2 Ghash/s. Only with some careful overclocking could the rig crank out a respectable number of hashes yet still remain at an efficiency ratio in the range of 2.0 Mhash/J .
Fast forward to today when Butterfly Labs offers for sale their BitForce SHA256 Mini Rig.
The base configuration of this rig contains 18 FPGA cards and costs $15,295 (plus s/h). The illustration above shows a rig holding its maximum 24 FTPA cards.
The result is the first time that 25 Ghash/s has ever had such a small physical footprint.
With power consumption at 1,250W the efficiency ratio hits 20.0 Mhash/J – a level that is 10 times more efficient than a GPU rig that is able to produce the same amount of hashing capacity.
The boards for the Mini Rig are custom built and the length of time required for foundry production causes the lead-time between the time of order through when shipment occurs to take between twelve to eighteen weeks after an order is placed.
The BitForce Single is still being sold (though it too has an order backlog) and eventually production of these will switch to begin using the same Rev3 board (as shown above) that the Mini Rig uses. Currently all production of the Rev3 cards (some of which are shown below) is going towards reducing the backlog for the Mini Rig.