Difficulty: 244,139, Total network hashing: 1,747 Ghash/sec
The recent difficulty threshold for generating bitcoins went from 157,426 to 244,139, representing a 55% increase in just under 10 days. The difficulty readjusts every 2,016 blocks and today this happened when block 124,992 was reached.
The hashing strength of the entire Bitcoin network is now at least 1,747 Ghash/second using the new difficulty measurement. Early calculations for the next adjustment indicate continued rapid growth however with nearly two weeks left before that happens there’s little certainty as to what level will be reached.
It is quite possible though that difficulty will increase another 30% or more, especially considering the current high levels in the BTC/USD market rate.
Supplies of certain models of GPU hardware desired by miners, such as the ATI Radeon HD 58XX and 59XX have sold out globally now that the manufacturer no longer produces them. At the same time, supplies for the latest high-end graphics card, the AMD Radeon HD 6990 remain very tight.
Miners not using the high-end hardware, most of whom who already are in pools, are finding that their existing mining capacity yields less and less with each jump in difficulty. The mining profitability level is high enough yet that few except for those running the most inefficient hardware will continue mining.
New capacity is coming not just from individuals entering mining and adding a second or third rig, but from those doing so commercially, including a recent rush of those wanting to raise equity to start commercial mining operations.
A higher total network hashing strength allows there to be greater trust that an attacker cannot control, exclude or modify the ordering of transactions processed as the result of mining activity. But by some estimates, the Bitcoin network now has as much computing power as half of all the Top 500 Supercomputer projects combined.
Some in the Bitcoin community believe that “too much computational power is being expended to protect too little value”. Whether or not any alternatives to Bitcon’s proof-of-work method would be successful however is a topic up for debate.
Mining difficulty lags price and has quite some distance to go yet before it catches up to the level after the market price rallied. If the price stays elevated, or increases from here, GPU miners might face a threat from one or more of the capital-intensive FPGA and ASIC initialtives.
Until that time though, there’s another difficulty adjustment period or two for miners to continue reaping the rewards.