40 minute BTC block time - No big deal

[ncsupanda]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

[adamstgBit]

bad luck and new mining difficulty

[ncsupanda]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

Me sending a tx.

You just HAD to go and spend your millions of Bitcoin in a single TX.

[justusranvier]

What could lead to such a long wait?

http://en.wikipedia.org/wiki/Poisson_distribution

[jonald_fyookball]

bad luck and new mining difficulty

my understanding is that the difficulty is based off of how many leading zeros are in the hash of the nonce.
The smallest increase in difficulty is adding one additional zero, correct?  by what order of magnitude does this increase the difficulty?

[ncsupanda]

What could lead to such a long wait?

http://en.wikipedia.org/wiki/Poisson_distribution

Makes sense (trying to draw back to my required Statistics course), so is the reasoning found in the difficulty and luck calculations?

[CEG5952]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

Bad luck, basically.

It really sucks -- it seems lately anytime I send a bitcoin payment, I end up on the block where it takes 1+ hour for a confirmation. I dread when I send a payment, and look to the see the last blocks at like "1 min, 4 min, 8 min" and then I know I might be in for a wait. Gambler's fallacy aside....

[jonald_fyookball]

What could lead to such a long wait?

http://en.wikipedia.org/wiki/Poisson_distribution

Makes sense (trying to draw back to my required Statistics course), so is the reasoning found in the difficulty and luck calculations?

not really.  Poisson just describes distribution of solving time based on 10 min average and no dependencies between one block and the next.

[justusranvier]

http://en.wikipedia.org/wiki/Exponential_distribution

http://www.stat.berkeley.edu/~stark/Java/Html/ProbCalc.htm

[zimmah]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

variance.

10 minute block time is on average, sometimes 4 blocks can be found in 10 minutes, and other times 40 minutes can pass without finding a block.

it's a random process.

[ncsupanda]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

variance.

10 minute block time is on average, sometimes 4 blocks can be found in 10 minutes, and other times 40 minutes can pass without finding a block.

it's a random process.

So essentially as long as it averages out to roughly 10 minutes the process works exactly as planned? Haven't actually looked at the source to see where variance is accounted for. Thank you for this.

[ShakyhandsBTCer]

Pretty interesting, to say the least. It's been a while since I've seen a really large block time, so I think it calls to ask: What could lead to such a long wait?

variance.

10 minute block time is on average, sometimes 4 blocks can be found in 10 minutes, and other times 40 minutes can pass without finding a block.

it's a random process.

So essentially as long as it averages out to roughly 10 minutes the process works exactly as planned? Haven't actually looked at the source to see where variance is accounted for. Thank you for this.

It is expected that blocks will not be found exactly once every 10 minutes, but rather, on average once every 10 minutes. When the average block time goes under 10 minutes then the difficulty will increase and when the average block time is over 10 minutes the difficulty will decrease, this is check ever 2016 blocks

[BurtW]

bad luck and new mining difficulty

my understanding is that the difficulty is based off of how many leading zeros are in the hash of the nonce.
The smallest increase in difficulty is adding one additional zero, correct?  by what order of magnitude does this increase the difficulty?

No, the difficulty is not adjusted in huge four bit increments (adding another zero), the difficulty is adjusted in much finer detail, read this:

https://en.bitcoin.it/wiki/Difficulty

The current target is here:  

http://blockexplorer.com/q/hextarget

and it is:  0x0000000000000000415FD1000000000000000000000000000000000000000000

"The SHA-256 hash of a block's header must be lower than or equal to the current target for the block to be accepted by the network."

So it must be less than or equal to the number shown above, until the next adjustment.

Oh, to answer your question directly "adding another zero" is a shift by 4 bits so it would increase the difficulty by 2⁴ = 16 times the previous difficulty = a 1600% increase in the difficulty.

[jonald_fyookball]

thx Burt...yeah didnt really understand the article.
too much thinking for a Sunday

I guess my question is: whats the granularity of the difficulty changes?

[BurtW]

thx Burt...yeah didnt really understand the article.
too much thinking for a Sunday

I guess my question is: whats the granularity of the difficulty changes?

"The largest legal value for this field is 0x7fffff"

The number has 6 bytes for the mantisa minus the sign bit so the minimum change is 1 part in 2²³ = a minimum change of about 0.00001192%

In other words changing the target from:

0x0000000000000000415FD1000000000000000000000000000000000000000000 to
0x0000000000000000415FD2000000000000000000000000000000000000000000

is a very tiny adjustment.

[chaosPT]

You call a 40min long ?

I have waited for hours before .

[Lauda]

This isn't a surprise though, it happens.

[Meuh6879]

I have waited for hours before .

+1


timecode of block here : http://blockr.io/block/list/


block 308511 and 308512 = 52min

[ShakyhandsBTCer]

bad luck and new mining difficulty

my understanding is that the difficulty is based off of how many leading zeros are in the hash of the nonce.
The smallest increase in difficulty is adding one additional zero, correct?  by what order of magnitude does this increase the difficulty?

No, the difficulty is not adjusted in huge four bit increments (adding another zero), the difficulty is adjusted in much finer detail, read this:

https://en.bitcoin.it/wiki/Difficulty

The current target is here:  

http://blockexplorer.com/q/hextarget

and it is:  0x0000000000000000415FD1000000000000000000000000000000000000000000

"The SHA-256 hash of a block's header must be lower than or equal to the current target for the block to be accepted by the network."

So it must be less than or equal to the number shown above, until the next adjustment.

Oh, to answer your question directly "adding another zero" is a shift by 4 bits so it would increase the difficulty by 2⁴ = 16 times the previous difficulty = a 1600% increase in the difficulty.

I am pretty sure that I read somewhere that the maximum the difficulty can increase each 2016 block period is (was) 4x the current difficulty

[factor280]

The more we hash... the longer it's gonna take. Crazy its at 40 minutes though.