http://www.coindesk.com/inside-butterfly-labs-the-asic-bitcoin-mining-arms-race/In the previous FPGA generation, processing was measured in hundreds of megahashes. The current generation of Bitcoin miners perform at a speed of gigahashes. The most powerful unit that Butterfly Labs offers is the 500 gigahash per second Mini Rig SC, currently priced at $22,484. It comes with a Nexus 7 tablet that has a custom built BFL app for mining bitcoins, which is also known as a “host” device since the miners need a software application to tell them what to do.
