Bitcoin Forum

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?

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.

You're really looking at a 3 block window and claiming ASICs? Really?

It's possible there are errors in reporting hash rate, if the reward is factored in anywhere in the calculation.

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.

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.

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.

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.

This always happens after a difficulty change.  Check back in a few days.

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

We didn't just have a diff change though. Yesterday's numbers were perfectly normal.

I think this is what happened... Lots of people turned on to finish the 50BTC blocks...

This always happens when the reward halves... so far at least.

I laughed.

How does this always happen when this is the first time it's halved?

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.

FTW

I have free power.. Friend of mine hosts my rigs at his apartment.

https://i.imgur.com/LO4Ybl.png (http://bitcoin.sipa.be/)

I'd say it's significant. Assuming ASIC-testing.

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.

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.

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.

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.

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.

How many times has it NOT happened?

YOU ARE AN IDIOT!

#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.

Bitminter's run of luck today happened because i turned off my GPU miners and fired up my FPGA's which arrived today  ;D ;D ;D ;D ;D

Why so happy? You will never pay them off.  Or I am missing something?

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.

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...

ASIC testing, isn't that the most probably answer?

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

https://i.imgur.com/DdJag.png

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.

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.

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?

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..

:)

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.

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.

Where we at now?

Well, at the moment we're looking at a 3% difficulty increase on the next reset.

Not really dropping then is it...