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Topic: Huge difficulty spike after Halving -- coincidence? (Read 5831 times)

sr. member
Activity: 330
Merit: 250
Not really dropping then is it...
sr. member
Activity: 392
Merit: 250
Where we at now?

Well, at the moment we're looking at a 3% difficulty increase on the next reset.
sr. member
Activity: 330
Merit: 250
Where we at now?
hero member
Activity: 481
Merit: 500
Difficulty is crashing now. I went through this last year when the price was dropping and thus making mining unprofitable for everyone. As it hit $4, I thought I'd have to turn off my miners, but the difficulty kept dropping, keeping me riding the profitability line. I was on both sides at different times, but I didn't care that much since I was also mining for principle and support of the network. I was never more than 10% unprofitable. From that it seemed to me that most GPU miners either paid more than I do in electricity (11c/kwh) or they didn't have cards as efficient as I (1.42 MHps/W measured at the wall). That system right now would be -1.5% profitable which in past experience has people turning off their rigs.

Wow, do you undervolt your cards? I've tried undervolting but wasn't successful.   Mine is 2.3 something, much worse than yours.
hero member
Activity: 588
Merit: 500
firstbits.com/1kznfw
Difficulty is crashing now. I went through this last year when the price was dropping and thus making mining unprofitable for everyone. As it hit $4, I thought I'd have to turn off my miners, but the difficulty kept dropping, keeping me riding the profitability line. I was on both sides at different times, but I didn't care that much since I was also mining for principle and support of the network. I was never more than 10% unprofitable. From that it seemed to me that most GPU miners either paid more than I do in electricity (11c/kwh) or they didn't have cards as efficient as I (1.42 MHps/W measured at the wall). That system right now would be -1.5% profitable which in past experience has people turning off their rigs.
sr. member
Activity: 330
Merit: 250
I took my GPU overclock from reliable 24/7 to max power. I did it to squeeze out the last drops of 50btc blocks. Maybe others did something similar.
Also still profitable at 25btc.
Maybe you overestimated how many would have to shut down.
Besides nothing better to do till the ASICs arrive.
Maybe people are anticipating price increases rather than react to the historical "price sets difficulty ratio" maybe miners are becoming more forward looking.
legendary
Activity: 1002
Merit: 1000
Bitcoin
To those who call GPU MINING now unprofitable.. At current diff, with my power cost, my GPU will still be profitable as long as the price is over 5$...
Anyway, I buy and mine..

Smiley
hero member
Activity: 602
Merit: 500
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?

Half price for FPGA's, and no ASIC's shipping this year due to flaws found in their designs. They'll pay for themselves before any ASIC's start shipping. When that happens they'll be reprogrammed for other tasks.
With current difficulty and price you'll need ~8 months to pay them off, assuming half price for FPGA's and you paying nothing for electricity. ASICs will hit pretty soon, most probably Jan-Feb 2013...

http://www.tricone-mining.com/
My calculations at current difficulty/half reward and their current hashing rates says they'll pay off in ~8-10 weeks. Maybe less if GPU miners start dropping off the network due to unprofitablilty.
I somehow doubt we'll see any real working ASIC's until Feb/March at the earliest and thats if they don't have any further delays/issues from what they've already experienced.

Just for fun I calculated this out, at 315MH/sec, no electrical costs, current difficulty, and 10 week payoff, you would have had to get each board + chip for $40/chip (free board), or for a ~950MH/sec setup, board + chips + fans + etc would have to be $120.

That sound right to you, or do you think you need to re-calc?
hero member
Activity: 535
Merit: 500
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?

Half price for FPGA's, and no ASIC's shipping this year due to flaws found in their designs. They'll pay for themselves before any ASIC's start shipping. When that happens they'll be reprogrammed for other tasks.
With current difficulty and price you'll need ~8 months to pay them off, assuming half price for FPGA's and you paying nothing for electricity. ASICs will hit pretty soon, most probably Jan-Feb 2013...

http://www.tricone-mining.com/
My calculations at current difficulty/half reward and their current hashing rates says they'll pay off in ~8-10 weeks. Maybe less if GPU miners start dropping off the network due to unprofitablilty.
I somehow doubt we'll see any real working ASIC's until Feb/March at the earliest and thats if they don't have any further delays/issues from what they've already experienced.
You've got a major error somewhere in your calculations. Try this one http://bitcoinx.com/profit/index.php
 Assuming that you have bfl singles and paid for each 300$, then hardware break even is 235 days without electricity cost.
full member
Activity: 143
Merit: 100
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?

Half price for FPGA's, and no ASIC's shipping this year due to flaws found in their designs. They'll pay for themselves before any ASIC's start shipping. When that happens they'll be reprogrammed for other tasks.
With current difficulty and price you'll need ~8 months to pay them off, assuming half price for FPGA's and you paying nothing for electricity. ASICs will hit pretty soon, most probably Jan-Feb 2013...

http://www.tricone-mining.com/
My calculations at current difficulty/half reward and their current hashing rates says they'll pay off in ~8-10 weeks. Maybe less if GPU miners start dropping off the network due to unprofitablilty.
I somehow doubt we'll see any real working ASIC's until Feb/March at the earliest and thats if they don't have any further delays/issues from what they've already experienced.
donator
Activity: 2772
Merit: 1019

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.


#2 is my guess. Folks turned on their miners for the day to enjoy the final hours of 50BTC reward. Now that it's past, they have to keep them on long enough to exceed the withdrawl minimum so they claim the fruits of their labors. But it's taking longer than expected since the reward rate is now half what it used to be.

then why is it continuing? (EDIT: sorry, I didn't even read your explanation, but think it's unlikely)



it looks more and more significant (not variance) to me.

Draw a straight line through the graph for the past 6 months and it looks like the difficulty is averaging out. Also that spike is less than the spike exactly 1 month ago

Ok, maybe it's not decisive at all at this point. In fact one would probably have to "normalize" for price when making such judgements.
full member
Activity: 143
Merit: 100

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.


#2 is my guess. Folks turned on their miners for the day to enjoy the final hours of 50BTC reward. Now that it's past, they have to keep them on long enough to exceed the withdrawl minimum so they claim the fruits of their labors. But it's taking longer than expected since the reward rate is now half what it used to be.

then why is it continuing? (EDIT: sorry, I didn't even read your explanation, but think it's unlikely)



it looks more and more significant (not variance) to me.

Draw a straight line through the graph for the past 6 months and it looks like the difficulty is averaging out. Also that spike is less than the spike exactly 1 month ago
donator
Activity: 2772
Merit: 1019

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.


#2 is my guess. Folks turned on their miners for the day to enjoy the final hours of 50BTC reward. Now that it's past, they have to keep them on long enough to exceed the withdrawl minimum so they claim the fruits of their labors. But it's taking longer than expected since the reward rate is now half what it used to be.

then why is it continuing? (EDIT: sorry, I didn't even read your explanation, but think it's unlikely)



it looks more and more significant (not variance) to me.
donator
Activity: 2772
Merit: 1019
1. If it were just BTCguild's luck, it should be leveling off at some point. Instead, the estimated next difficulty just keeps going up.

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.

3. As for "some people don't realize GPU mining isn't profitable anymore", that wouldn't explain an INCREASE in hashing power. It would only explain hashing power staying the same.


So we still don't have the answer.


ASIC testing, isn't that the most probably answer?
hero member
Activity: 535
Merit: 500
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?

Half price for FPGA's, and no ASIC's shipping this year due to flaws found in their designs. They'll pay for themselves before any ASIC's start shipping. When that happens they'll be reprogrammed for other tasks.
With current difficulty and price you'll need ~8 months to pay them off, assuming half price for FPGA's and you paying nothing for electricity. ASICs will hit pretty soon, most probably Jan-Feb 2013...
full member
Activity: 143
Merit: 100
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?

Half price for FPGA's, and no ASIC's shipping this year due to flaws found in their designs. They'll pay for themselves before any ASIC's start shipping. When that happens they'll be reprogrammed for other tasks.
vip
Activity: 1358
Merit: 1000
AKA: gigavps
This stuff really only makes sense averaged over a multi-week period.

http://blockorigin.pfoe.be/chart.php

pfoe.be shows it pie chart over the last 2016 blocks to try and get rid of the noise. They also track blocks by parsing individual pool websites instead of guessing ip addresses like blockchain.
hero member
Activity: 535
Merit: 500
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
Why so happy? You will never pay them off.  Or I am missing something?
full member
Activity: 143
Merit: 100
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.


Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  Grin Grin Grin Grin Grin
hero member
Activity: 561
Merit: 500

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.


#2 is my guess. Folks turned on their miners for the day to enjoy the final hours of 50BTC reward. Now that it's past, they have to keep them on long enough to exceed the withdrawl minimum so they claim the fruits of their labors. But it's taking longer than expected since the reward rate is now half what it used to be.
sr. member
Activity: 285
Merit: 250
How does this always happen when this is the first time it's halved?


YOU ARE AN IDIOT!
hero member
Activity: 778
Merit: 1002
How does this always happen when this is the first time it's halved?

How many times has it NOT happened?
donator
Activity: 1731
Merit: 1008
The increase in difficulty started before the halving. The halving was supposed to be at 1pm, and it got pushed up 3 hours overnight.

I don't think it's ASICs, it's people turning on their dusty miners for a shot at history.

Many people will continue mining in spite of non-profitability. Some do it because they believe in bitcoin, others because they believe bitcoin price will rise and justify their actions (this is actually wrong because they could instead just buy some bitcoin if they think price will rise). Meanwhile, on the price side of things, you can really only expect it to rise at most at a rate that would eat through the order book at half the average volume.

I do both, I mine and I buy because I know BTC will rise in price... better than buying stock.. IMO...

What do you do for diner ?

/Seriously,  Do you really think a sufficient number of miners care much about finding the last 50btc block to affect hashrate in any visible way ? It has very little historical value, the chance of finding is extremely small, It require that you mine Solo,  90%+ of miners don't.  GPU mining is still profitable for many, but it as not profitable enough to restart a mining farm for less than a day.
hero member
Activity: 588
Merit: 500
firstbits.com/1kznfw
The increase in difficulty started before the halving. The halving was supposed to be at 1pm, and it got pushed up 3 hours overnight.

I don't think it's ASICs, it's people turning on their dusty miners for a shot at history.

Many people will continue mining in spite of non-profitability. Some do it because they believe in bitcoin, others because they believe bitcoin price will rise and justify their actions (this is actually wrong because they could instead just buy some bitcoin if they think price will rise). Meanwhile, on the price side of things, you can really only expect it to rise at most at a rate that would eat through the order book at half the average volume.
sr. member
Activity: 392
Merit: 250
1. If it were just BTCguild's luck, it should be leveling off at some point. Instead, the estimated next difficulty just keeps going up.

2. If it were just ex-miners firing up their rigs for old times sake/to find the last 50BTC block, they must be leaving them on for a while longer.

3. As for "some people don't realize GPU mining isn't profitable anymore", that wouldn't explain an INCREASE in hashing power. It would only explain hashing power staying the same.


So we still don't have the answer.
donator
Activity: 1731
Merit: 1008
I have really cheap energy 0.07Kw/h and I will continue mining.. my goal is long LONG term so I dont care about halving.. I care about hoarding...but eventually, when 2Ghash make less than .20 BTC per day, then I might upgrade to sopmething different...
Smiley
So you're the cause of the spike ? Good to know.

Seriously, There was ~18 block in the time it's supposed to take for 9, this could be an extra ~20ghs in a relatively small time span.
legendary
Activity: 1750
Merit: 1007
If you look at blockchain.info before the reward halving, you can see where a lot of that spike came from.  Bitminter and BTC Guild both had especially nice runs of luck for about 12 hours preceeding the change.  BTC Guild's luck alone would have been interpreted as a ~2-2.5 TH/s increase in overall network speed for those 12 hours, and even a few hours after.
donator
Activity: 2772
Merit: 1019


I'd say it's significant. Assuming ASIC-testing.
hero member
Activity: 1078
Merit: 502
I have free power.. Friend of mine hosts my rigs at his apartment.
hero member
Activity: 728
Merit: 540
This always happens when the reward halves... so far at least.

FTW
legendary
Activity: 1484
Merit: 1026
In Cryptocoins I Trust
Anyone that doesn't frequent these forums probably doesn't realize that GPU mining is not profitable anymore.

It might take a month or so for people to figure it out and sell their rig or mine ALT coins instead.

And of course there are the free power people, who I imagine will continue GPU mining until their GPUs die. But, I can't imagine there's a whole lot of these types.
hero member
Activity: 1078
Merit: 502
How does this always happen when this is the first time it's halved?
hero member
Activity: 602
Merit: 500
This always happens when the reward halves... so far at least.

I laughed.
hero member
Activity: 778
Merit: 1002
This always happens when the reward halves... so far at least.
hero member
Activity: 1078
Merit: 502
That fact that a lot of people powered up their rigs to specifically try and mine blocks #209999 & #210000 could also have had a part in this.


I think this is what happened... Lots of people turned on to finish the 50BTC blocks...
sr. member
Activity: 392
Merit: 250
This always happens after a difficulty change.  Check back in a few days.

I am well aware of what happens after a difficulty change; I've been mining Bitcoins since May 2011  Wink

We didn't just have a diff change though. Yesterday's numbers were perfectly normal.
hero member
Activity: 882
Merit: 1006
That fact that a lot of people powered up their rigs to specifically try and mine blocks #209999 & #210000 could also have had a part in this.
sr. member
Activity: 257
Merit: 250
Not trusting third parties with my private keys
This always happens after a difficulty change.  Check back in a few days.
sr. member
Activity: 392
Merit: 250
The short term network hashrate is always volatile.  A change of 3TH/s, 5TH/s, or even 10TH/s isn't particularly meaningful.

http://bitcoin.sipa.be/speed-lin-2k.png

Now if over the next 3 days the 3 day moving average increases by more than say ~2TH/s you might have something other than just noise.

I don't know... that 3-day moving average line seems to be spiking upward. Unless it crashes down REAL fast in the next half-day, we're looking at an increase of network hashing power.

This is especially strange because I expected the total TH/s to slow down a bit, if anything.
sr. member
Activity: 322
Merit: 250


Re:  Variance.  True.

But.


FPGA shipments have been completed.  Anyone purchasing GPU's right now is not acting rationally.

Turning on already purchased GPU to offset heating bills is plausible.  I would be surprised if such practice would account for more than 1 TH.


A sustained multi TH increase would be very odd given the environment.
donator
Activity: 1218
Merit: 1080
Gerald Davis
The short term network hashrate is always volatile.  A change of 3TH/s, 5TH/s, or even 10TH/s isn't particularly meaningful.

http://bitcoin.sipa.be/speed-lin-2k.png

Now if over the next 3 days the 3 day moving average increases by more than say ~2TH/s you might have something other than just noise.
hero member
Activity: 602
Merit: 500
You're really looking at a 3 block window and claiming ASICs? Really?

It's not a 3 block window.

At first, I was a bit confused -- I thought "of course the estimate is off, the difficulty just reset" but it DIDN'T JUST RESET -- we just had a block halving.
A block reward halving shouldn't affect the calculation of block/hour and so forth.
Right?


Yes you are correct. This thread is spooky, with me agreeing with you so much.
sr. member
Activity: 392
Merit: 250
You're really looking at a 3 block window and claiming ASICs? Really?

It's not a 3 block window.

At first, I was a bit confused -- I thought "of course the estimate is off, the difficulty just reset" but it DIDN'T JUST RESET -- we just had a block halving.
A block reward halving shouldn't affect the calculation of block/hour and so forth.
Right?
newbie
Activity: 24
Merit: 0
It's possible there are errors in reporting hash rate, if the reward is factored in anywhere in the calculation.
legendary
Activity: 952
Merit: 1000
You're really looking at a 3 block window and claiming ASICs? Really?
hero member
Activity: 602
Merit: 500
You're a blast from the past man, same old stuff too.

However in this case I'm actually kinda on board with your notions. We're a number of hours ahead of schedule for block halving, and this is a big spike.

However I'm gonna remain calm, and suggest that's just the way the cookie has crumbled. blockchain.info (I know it only guesses at block origins) shows an unusual number of quick blocks, 21009 was found in 2 minutes by BTC guild, 21010 was found in 3 minutes after that by BTC guild (the pools hashrate has remained fairly constant). The unknowns have increased but that could be attributable to people wanting in on the last 50 blocks going solo.

So for now, I'm just gonna say variance.
sr. member
Activity: 392
Merit: 250
Blocks   210003
Total BTC   10.500M
 
Difficulty   3438909
Estimated   3496486 in 1677 blks
 
Network total   30.949 Thash/s
Blocks/hour   7.54 / 477 s

I know, variance... but 3 Thash/S is quite a bit to write off as variance, especially since a FEW people at least (maybe quite a few?) are shutting off their GPU rigs this morning.

I've been checking
http://bitcoincharts.com/markets/

a lot lately, with this halving coming up (and now past us).

I must say I was shocked at what I saw this morning -- it's as if someone was waiting until after the halving to turn on his ASIC array!
Maybe one of the companies is shipping ASICs?

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