Bitcoin has been all over the news this past week. I think the main trigger was some significant price swings on the exchange rate. Then there were follow-on stories talking about how mining activities are using $150,000 in electricity every day.
Even if you don't care about alternative currencies, you may find the hardware used to enable "mining" for coins to be of interest. Here's a story talking about said hardware: http://gizmodo.com/5994446/digital-drills-the-monster-machines-that-mine-bitcoin The basic idea with Bitcoin is that you have a computer do some intensive computational work, specifically compute hashes: http://en.wikipedia.org/wiki/Bitcoin#Bitcoin_mining The mining process or proof-of-work process involves scanning for a value that when hashed with SHA-256, the hash begins with a number of zero bits. The average work required is exponential in the number of zero bits required, but can always be verified by executing a single hash. And your reward for doing the work is you get a coin, which can be exchanged for goods and services, or for US dollars on an exchange. A clever part of the design is that it self-adjusts for the ever increasing capabilities of the available hardware: To compensate for increasing hardware speed and varying interest in running nodes over time, the proof-of-work difficulty is determined by a moving average targeting an average number of blocks per hour. If they're generated too fast, the difficulty increases. And this has led to: Today, bitcoin mining is a competitive field. An arms race has been observed through the various hashing technologies that are used to mine bitcoins and confirm transactions: High-end GPUs (Graphical Processing Units) common in many gaming computers, FPGAs (Field Programmable Gate Arrays) and ASICs (Application-specific integrated circuits) all have been used. The newest addition, ASICS, are built into specialized servers that can cost nearly $3000 USD a unit. Also listen to: http://www.grc.com/sn/past/2011.htm#287 for Steve Gibson's explanation of how the algorithm works. In any case, the competition and the cost of power is driving miners to FPGAs and ASICs. Pretty amazing that this made up currency scheme has been profitable enough to justify the development of ASICs. I have to assume that with this degree of profit motive, there must be criminal organizations using zombie bot networks to do mining. When the cost of the hardware and electricity is free, you clearly have an advantage. The Gizmodo article has some interesting pictures showing racks of open-frame computers, from CPU-era to GPU-era to FPGAs and finally ASICs. They describe on ASIC solution (quoting Gizmodo): Meet the Avalon ASIC. ... Inside its unassuming grey case is an army of specialty chips that promise 65 gigahashes per second. This is $6,800 equipment...that, properly utilized, stands to be worth much more. [...] And while Avalon started the revolution, others are not far behind. Companies like ASICMiner, Butterfly Labs, and bASIC all offer similar systems--some that boast even more power--but none of those have managed to ship. [...] The Butterfly Labs BitForce Mini Rig SC, a 1,500 GHz/s machine. It's about 30 times more powerful than then current Avalon ASICs, or would be if it ever exists... [...] Bitcoin has always favored early adopters, bold ones especially. Because mining difficulty increases to compensate for increased power, all advantages are temporary. But it doesn't increase dynamically. Instead it hops up once every 14 days, so advantages can be leveraged. The first Avalon ASIC to be put to use paid for itself in a mere nine days, but every additional unit follows will have more and more ground to make up. The treatment of the tech in this article is a bit superficial. It would have been nice if they described in more detail what was depicted in each photo. But probably a decent overview of the hardware, if you only have a casual interest in Bitcoins. A concluding thought: Ultimately, ASIC devices are the last great innovation in Bitcoin mining; once you've specialized down to the chipset, there's nowhere left to turn for a 100-fold computing power increase. And in that way, we're seeing the beginning of the end of the gold rush, just as Bitcoin fever reaches a fever-pitch. That's kind of a defeatists view, and doesn't seem to acknowledge Moores law. Over time the ASICs will shrink and you'll see more hashing engines per chip. How about Quantium computing? More likely, the next innovation will come not from hardware but from mathematics - finding an algorithmically more efficient way of arriving at the same result. -Tom _______________________________________________ Hardwarehacking mailing list Hardwarehacking@blu.org http://lists.blu.org/mailman/listinfo/hardwarehacking
