Spreadsheet:
- https://docs.google.com/spreadsheet/ccc?key=0AmcTCtjBoRWUdHVRMHpqWUJValI1RlZiaEtCT1RrQmc
[oops, time to update it]
Topic: Does anyone remember the last time BTC difficulty retargeted Lower? (Read 1511 times)
April 19, 2013, 07:00:20 PM
Excellent answer guys.
thank you.
thank you.
April 19, 2013, 05:18:28 PM
The last time difficulty adjusted downward was 8 adjustments (~16 weeks) ago . The "stairstep" line in the graph above is the difficulty adjustment.
As indicated above difficulty only adjusts every 2016 blocks. So if you are looking at the current hour and saying "the network is too slow" well you are just looking at variance not a change in hashing power.
At 10 minutes per block, 2016 blocks should take 20,160 minutes (or 15 days). None of the 7 prior difficulty adjust periods took more than 20,160 minutes thus the average number of blocks per hour was >10 minutes thus difficulty rose.
Every 2016 blocks the network looks at the timespan between the last block and the block 2016 blocks prior. The target is for that timespan to be 20,160 minutes. The network then computes the difficulty that would have been necessary for the prior 2016 blocks to meet the target and adjusts the difficulty to that. Say at the next adjustment the timestpan between the current block and the block 2016 blocks prior is 19,152 minutes and difficulty is 8974296.0148879 then the new difficulty is 5.26% higher ( 20,160 / 19,152 ) = 1.0526. 8974296.0148879 * 1.0526 = 9446627.38409252.
April 19, 2013, 05:13:42 PM
Difficulty retargets ever 2016 blocks. If blocks are being solved, on average, faster than every 10 minutes, difficulty adjusts up. With the recent increase in media coverage, the price going up, etc (which may be bringing old miners back on board) and ASICs rolling out, difficulty has been going up pretty consistently lately.
It has gone down in the past, but I don't have the graph in from of me to say exactly when the last time was that it happened though.
Edit:
Look like it has gone down most recently in Feb 2013, Jan 2013:
http://bitcoin.sipa.be/speed-lin.png
It has gone down in the past, but I don't have the graph in from of me to say exactly when the last time was that it happened though.
Edit:
Look like it has gone down most recently in Feb 2013, Jan 2013:
http://bitcoin.sipa.be/speed-lin.png
April 19, 2013, 04:45:06 PM
Maybe im reading the data wrong at Bitcoinwatch.com.
It seems to me that every time the Difficulty retargets, it goes higher. Even if the hashrate for the network is low.
maybe i dont understand but it hought the btc code was designed to approximate 10 blocks per hr...we currently get 6-8.
need less difficulty?
code not adjust properly?
what are your thoughts?
It seems to me that every time the Difficulty retargets, it goes higher. Even if the hashrate for the network is low.
maybe i dont understand but it hought the btc code was designed to approximate 10 blocks per hr...we currently get 6-8.
need less difficulty?
code not adjust properly?
what are your thoughts?
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