Bitcoin Forum
June 21, 2024, 07:32:57 PM *
News: Latest Bitcoin Core release: 27.0 [Torrent]
 
   Home   Help Search Login Register More  
Pages: [1]
  Print  
Author Topic: Does anyone remember the last time BTC difficulty retargeted Lower?  (Read 1494 times)
Shad3dOne (OP)
Sr. Member
****
Offline Offline

Activity: 261
Merit: 250


Interesting.....


View Profile WWW
April 19, 2013, 09:45:06 PM
 #1

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?

Domain for sale -> NXTcoin.com, 200 btc/2.9 M nxt. pm me
like craigslist but for btc! --> Visit BTClist.com
FederationCredits--> C6khbXzADRUeT9di2SpNubCt2UVTuayKMV What's this?
MashRinx
Sr. Member
****
Offline Offline

Activity: 389
Merit: 250



View Profile
April 19, 2013, 10:13:42 PM
 #2

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
DeathAndTaxes
Donator
Legendary
*
Offline Offline

Activity: 1218
Merit: 1079


Gerald Davis


View Profile
April 19, 2013, 10:18:28 PM
 #3



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.
Shad3dOne (OP)
Sr. Member
****
Offline Offline

Activity: 261
Merit: 250


Interesting.....


View Profile WWW
April 20, 2013, 12:00:20 AM
 #4

Excellent answer guys.

thank you.

Smiley

Domain for sale -> NXTcoin.com, 200 btc/2.9 M nxt. pm me
like craigslist but for btc! --> Visit BTClist.com
FederationCredits--> C6khbXzADRUeT9di2SpNubCt2UVTuayKMV What's this?
Stephen Gornick
Legendary
*
Offline Offline

Activity: 2506
Merit: 1010


View Profile
April 20, 2013, 04:27:56 AM
 #5

Spreadsheet:

 - https://docs.google.com/spreadsheet/ccc?key=0AmcTCtjBoRWUdHVRMHpqWUJValI1RlZiaEtCT1RrQmc
[oops, time to update it]

Unichange.me

            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █
            █


Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!