Bitcoin Forum
December 04, 2016, 02:21:42 PM *
News: To be able to use the next phase of the beta forum software, please ensure that your email address is correct/functional.
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: How Does BitcoinCharts.com Know The Network Total Hashes/Second?  (Read 1030 times)
gigabytecoin
Sr. Member
****
Offline Offline

Activity: 280


View Profile
April 06, 2011, 08:03:13 AM
 #1

As seen in the top all black nav bar of http://bitcoincharts.com/markets/

How do they determine the number of terahashes/second, currently at 0.735 Thash/sHuh

Isn't a hash only submit to the network once it has been deemed to be below the target value?

Is the network hash rate just an estimate?
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1480861302
Hero Member
*
Offline Offline

Posts: 1480861302

View Profile Personal Message (Offline)

Ignore
1480861302
Reply with quote  #2

1480861302
Report to moderator
1480861302
Hero Member
*
Offline Offline

Posts: 1480861302

View Profile Personal Message (Offline)

Ignore
1480861302
Reply with quote  #2

1480861302
Report to moderator
1480861302
Hero Member
*
Offline Offline

Posts: 1480861302

View Profile Personal Message (Offline)

Ignore
1480861302
Reply with quote  #2

1480861302
Report to moderator
Grinder
Legendary
*
Offline Offline

Activity: 1269


View Profile
April 06, 2011, 09:15:02 AM
 #2

I think it's guessing using a combination of the known current difficulty and how quickly blocks are currently being solved.
Pieter Wuille
Legendary
*
Offline Offline

Activity: 1036


View Profile WWW
April 06, 2011, 09:50:19 AM
 #3

Is the network hash rate just an estimate?

Yes, and a very tough one to make.

aka sipa, core dev team

Tips and donations: 1KwDYMJMS4xq3ZEWYfdBRwYG2fHwhZsipa
gigabytecoin
Sr. Member
****
Offline Offline

Activity: 280


View Profile
April 06, 2011, 06:20:28 PM
 #4

Is the network hash rate just an estimate?

Yes, and a very tough one to make.

Ok thank god. I thought I was going nuts there for a second.

I'm a man of logic. And the speed with which that number sways every few hours doesn't make sense given the nature of mining.
Jim Hyslop
Member
**
Offline Offline

Activity: 98


View Profile
April 07, 2011, 03:56:25 AM
 #5

Is the network hash rate just an estimate?

Yes, and a very tough one to make.
Actually, it's not that hard.

The wiki states somewhere (can't find the page now, of course) that the probability of a single hash calculation solving a block is

      target
     -------
       2256

and the average number of hashes required to solve a block is its inverse:

       2256
     -------
     target

Let's call that last formula A. On average, then, it takes A hashes to solve a block. We know how long it takes to create a particular block (just take its creation timestamp and subtract the timestamp of the previous block from it). So the network hash rate is simply A / timespan.

Of course, individual blocks will be highly variable due to the random nature of finding a solution (there were about 3 or 4 blocks recently that were created within 5 minutes; the block before that series took 20 minutes, as did the block after). To get a more accurate estimate, you'd want to take the time over 50 or 100 blocks. The formula is:

      2256 * n
-----------------------
target * (tsN - tsN-n)

where
n is the number of blocks you're sampling
tsx is the timestamp of block number x
N is the latest block number (or whatever block number you want to end your sample range with)
and target is currently 0xCBBD000000000000000000000000000000000000000000000000

Like my answer? Did I help? Tips gratefully accepted here: 1H6wM8Xj8GNrhqWBrnDugd8Vf3nAfZgMnq
Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!