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Topic: Difficulty speculation for the round started on 29/6/13 (Read 2590 times)

hero member
Activity: 630
Merit: 500
That 10th period was really lucky one!
hero member
Activity: 572
Merit: 500
May I ask why you're doing this?  Smiley

There's a math puzzle factor to this and maybe a flip a coin aspect too.  But over the last 3-4 months difficulty changes have been sort of unpredictable - there was even a decrease if I remember correctly.  

All due to a looong list of factors that affect the total network hashrate, including the less obvious ones like homemade rig uptime lapses, to FPGAs being sent back to BFL, people going on holidays and just not caring, to individual miners switching to other pools, to solo, to other cryptocurrencies ....

Don't get me wrong I'm tracking things too but why such a real time approach?

No reason really. Just curious to see how its progressing.

Keep up the good work, I have several orders for ASIC equipment all expected to ship around Aug/Sep and if the diff is way too high then I will pull out as I don;t want a ROI to be longer than 3 months for what Ive paid as this data will give me an idea of were the Diff will be heading...
legendary
Activity: 1680
Merit: 1014
Next difficulty is predicted to be 25668640 in 2.2 days. Buckle up. Smiley
hero member
Activity: 630
Merit: 500
Linear extrapolation of elapsed time (seconds) per each step:


21.6% extrapolated increase.
24.35%  Embarrassed
legendary
Activity: 826
Merit: 1004
503: 24647153 / 21335329 = 1.1552        15.52%

Thanks again.
hero member
Activity: 630
Merit: 500
503: 24647153 / 21335329 = 1.1552        15.52%
legendary
Activity: 826
Merit: 1004
May I ask why you're doing this?  Smiley

There's a math puzzle factor to this and maybe a flip a coin aspect too.  But over the last 3-4 months difficulty changes have been sort of unpredictable - there was even a decrease if I remember correctly. 

All due to a looong list of factors that affect the total network hashrate, including the less obvious ones like homemade rig uptime lapses, to FPGAs being sent back to BFL, people going on holidays and just not caring, to individual miners switching to other pools, to solo, to other cryptocurrencies ....

Don't get me wrong I'm tracking things too but why such a real time approach?

No reason really. Just curious to see how its progressing.
newbie
Activity: 12
Merit: 0
May I ask why you're doing this?  Smiley

There's a math puzzle factor to this and maybe a flip a coin aspect too.  But over the last 3-4 months difficulty changes have been sort of unpredictable - there was even a decrease if I remember correctly. 

All due to a looong list of factors that affect the total network hashrate, including the less obvious ones like homemade rig uptime lapses, to FPGAs being sent back to BFL, people going on holidays and just not caring, to individual miners switching to other pools, to solo, to other cryptocurrencies ....

Don't get me wrong I'm tracking things too but why such a real time approach?
legendary
Activity: 826
Merit: 1004
Over the 9th period, the difficulty increased by about 3%. If the following periods were all at least 3% then the difficulty at the end of the round would be at least 30%. If difficulty starts to increase by more than 3% per period then the difficulty increase could be as high as 40% at the end of the round. The next period of two should shed some insight on whether to expect 20% or 40%.
hero member
Activity: 630
Merit: 500
Half way through the round now. There were major increases in difficulty at the beginning of the round. Do you think that was mostly due to hashing power or luck?
Last difficulty increase didn't really 'catch up' to the hashrate (http://bitcoin.sipa.be/speed-lin-10k.png). That's why calculations started high, and there is also a major increase in hashing power last few days. Mostly 'unknown' portion - http://blockorigin.pfoe.be/top.php has NO DATA for 10.5% of blocks found. Was 7% last week.
legendary
Activity: 826
Merit: 1004
Half way through the round now. There were major increases in difficulty at the beginning of the round. Do you think that was mostly due to hashing power or luck?
legendary
Activity: 826
Merit: 1004
1,260 (6/16) = 7.4%

Cheers. I woke up 20 blocks to late for that one.
hero member
Activity: 630
Merit: 500
1,260 (6/16) = 7.4%
hero member
Activity: 630
Merit: 500
Some crazy hashing today - 185 blocks generated! That's lots of luck, or 200,000TH/s!
newbie
Activity: 56
Merit: 0
Yes, correct.
Actually, equation for "Estimated new diff change" is larger, and involves difficulty. But it can be simplified to that simple form.

(D-B)/(C-A)*2016 is time (in seconds) that will be needed for full round, according to current average speed.
60*60*24*14 is ideal time for full round in case if network hash speed does not change. Basically, average hash speed from last round would take this much seconds on current difficulty for this round.

DIF - current difficulty
DIF_NEXT - next difficulty

next difficulty can be calculated from this:
DIF * (60*60*24*14) = DIF_NEXT * ((D-B)/(C-A)*2016)
or
DIF_NEXT = DIF * (60*60*24*14) / ((D-B)/(C-A)*2016)

Increase = (DIF_NEXT - DIF) / DIF
Increase = (DIF * (60*60*24*14) / ((D-B)/(C-A)*2016) - DIF) / DIF

if you simplify last formula then you will get
(target time) / (average time per block * 2016) - 1
hero member
Activity: 630
Merit: 500
Thanks. I think I understand:
A is first block in round (first block on diff change)
B is time of that block
C is block 'offset' into round
D is time of that block

Network is targeting to generate a block every 10 minutes (600 seconds), and is calculating new difficulty for that target every 2016 blocks. That gives 14 days (or 60*60*24*14 in seconds - 'target time').

(C-A) is number of blocks found in current round
(D-B) is time elapsed in current round (from first block A up to block C)
(D-B)/(C-A) is 'average time per block' in current round

Estimated new diff change we can get with:
(target time) / (average time per block * 2016) - 1
newbie
Activity: 56
Merit: 0
As for the data I'm using, it's just taken from http://bitcoincharts.com/
Do you know what metod is bitcoincharts.com using to estimate next difficulty? Is it sliding window of 2016 blocks?

I'm watching allchains.info.  Author says he is using the exact calcluation since last diff change. Right now there is 1652 blocks left in this round (18.06% blocks measured), with 9.43% increase. Bitcoincharts: 4.38%.
allchains.info use linear extrapolation method, you can easily do all these calculations by yourself:

1) go to http://blockexplorer.com/q/nethash/2016, take latest block number (currently: 243936). This is first block after difficulty change.
A = 243936

2) go to http://blockexplorer.com/b/243936 (or insert new block number from step 1 in case of difficulty change), click on "Raw block" link, copy value from field "time" (in this case: 1372515725). This
B = 1372515725

3) now take block number from step 1, add to it any value between 1 and 2015. In this case it will be 126, or 252, or 378, etc..
C = 243936 + 126 = 244062

4) go to http://blockexplorer.com/b/244062, click on link "Raw block", copy value from field "time" (1372584672)
D = 1372584672

Result formula:
(60*60*24*14)/((D-B)/(C-A)*2016)-1
Result is 0.096494409, that is ~9.65%


I don't know about http://bitcoincharts.com/ algorithm, unfortunately it is impossible for me to find missing values there. Anyway, with allchains approach difficulty increase estimation every 126 block is following:
126 (1/16): 9.65%
252 (2/16): 9.98%
378 (3/16): 10.04%
504 (4/16): 9.65%
legendary
Activity: 826
Merit: 1004
As for the data I'm using, it's just taken from http://bitcoincharts.com/
Do you know what metod is bitcoincharts.com using to estimate next difficulty? Is it sliding window of 2016 blocks?

I'm watching allchains.info.  Author says he is using the exact calcluation since last diff change. Right now there is 1652 blocks left in this round (18.06% blocks measured), with 9.43% increase. Bitcoincharts: 4.38%.

I'm not sure what method it's using.
hero member
Activity: 630
Merit: 500
As for the data I'm using, it's just taken from http://bitcoincharts.com/
Do you know what metod is bitcoincharts.com using to estimate next difficulty? Is it sliding window of 2016 blocks?

I'm watching allchains.info.  Author says he is using the exact calcluation since last diff change. Right now there is 1652 blocks left in this round (18.06% blocks measured), with 9.43% increase. Bitcoincharts: 4.38%.
legendary
Activity: 826
Merit: 1004
For a 30% increase in diff, network need a minimum of 50T of new hashing power. Not very likely in next 10 days.
Anyway, nice effort on your part. How are you calculating the data? Is there some webpage with calculations, or are you pulling data from blockchain?

10 Minirigs per day = 50 Th/s in 10 days. There's Avalon, ASICMiner, and BFL units coming online. Between the 3 of them, 50 Th/s over the next 10 days is certainly a possibility.

As for the data I'm using, it's just taken from http://bitcoincharts.com/

Also, my estimate will be based off the data I post here. That initial 30% guess is based on observations of the data over the past few days. We'll be able to see how it's progressing over the next few data points though.

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