Topic: What's your shutdown point? - page 5. (Read 11441 times)

I think you have the BUY and MINE reversed.

It isn't difficulty.  It is what difficulty represents.  Number of Hashes to make a block.

Difficulty * 2^32 = number of hashes per block.

Another way of looking at your numbers:

7,255,634,282,020,860 / (3120 * 1000 * 1000 * 60 * 60 ) = 646 hours.
It will take you 646 hours to find a block.

646 hours * 1.550kW =  1,001 kWh per block. (neto just about 1 MWh)  
Every block you find consumes 1,001 kWh of electricity.

10,01 kWh * $0.149/kWh = $149.
When you mine you are essentially buying a block for $149.  It doesn't matter if you buy it from the market or buy it from mining either way you are buying it.

$149/50 = $2.98.

If BTC are selling for MORE than $2.98 you should mine.
If BTC are selling for LESS than $2.98 you should buy.

In the winter you likely can reduce that by 1/3.  The energy consumed heats the house.  It likely isn't as cheap/efficient as using natural gas so we shouldn't consider it "free heat" but maybe "subsidized heat".  In the winter (if your rigs are in heated part of your house) maybe use $2.00 as the breakpoint.  In the summer if you need to AC to cool your house that adds about 30% additional electrical cost making your break even more like $4.00

So getting super complex.  The most efficient method to acquire coins.

In summer.  Price above $4 MINE.  Below $4 BUY.
In fall/spring.  Price above $3 MINE.  Below $3 BUY.  *if not needing to use AC or heat
In Winter.  Price above $2 MINE.  Below $2 BUY.

Of course when difficulty changes you will need to adjust but only the first number in the equation changes.  Number of hashes per block is simply difficulty * 2^32.

When I lose power, brownout happens etc.

So if I'm pulling ~1550 from the wall for rigs and cooling and getting ~3120 Mh/s, I'm at ~2MH/watt right? Why does your difficulty number have more commas than the national debt?  At $0.149/kWh what price am I better off buying coins?

I have none.

To me, Bitcoin is not a machine which converts electricity into dollars. To me, Bitcoin is

* An interesting research topic
* A charming community full of good spirits and ideas
* and, above all, a great chance for a structural change in the monetary system somewhere down the road.

Why should I let my personal greed allow to do damage to these interesting goals?

Moreover, I started mining at a time where it was not yet profitable. Why should I stop it now when it loses profitability?

Ok. I admit it: My utility bill was higher than I expected. 

But I also learned a lot from the community and this is the price to pay.

And: I do not have to mine 24 x 7 on all my GPU cards (12 x 7 is fine as well), and in winter I have a clear preference how to produce heat. 

Yeah, I understand your point, but it's not "idiots like me" that are the problem.  As I don't speculate, or buy and sell btc.  I simply take what I get from mining and actually find goods to purchase online.  Which helps the community in general.

If more people used their btc that way, the price wouldn't be this low...

Or  you must have some very inefficient cards and/or power supplies.  I built my rigs for efficiency.  80 plus gold power supplies 3x5970s (one of the most efficient cards in raw performance and likely the #1 efficient card in real world performance), single core underclocked 45W max semprons, USB drive, and AMD motherboard w/ everything in southbridge turned off (every watt helps).

 4 rigs w/ 3x5970 = ~2.2 to 2.35GH/s ea (plus water cooled workstation which now has 3x 5970s).  Get about 2MH/w from the wall across all 5 systems.  Actually it is closer to 2.15 MH/w but I have found the older rigs are slightly less efficient so I say 2MH/watt as a conservative "goal".

Current difficulty 7,255,634,282,020,860 hashes per block.
2MH/watt * 60 * 60 * 1000 = 7200000 MH / kWh

 7,255,634,282,020,860 /  ( 7200000 * 1000 * 1000 ) = 1007 kWh per block.  9 cents per kWh = $90.63 per block.  $90.63 / 50 = ~$1.80 per coin.

The three metrics that determine break even are:
a) system efficiency (how many MH per watt, highly efficient cards, good powersupplies, and watching overclocks to keep it above 2MH/watt)
b) difficulty (combined with a give us how many kWh per block)
c) electricity prices (varies some free to $0.44 per kWh)

I have a bunch of odd ball cards 5850s, 6950s, 6970s sitting in a box that I need to ebay.  With prices as low as they are and space being a premium I like a dense stack of only highly efficient 5970s. The hard part is finding more at reasonable prices.

Hope you are found out and fired. This is the reason why the price is so low. If all people competed evenly, then the price would be higher than currently but when some idiots like you get "free electricity" they cause the price to fall as they can afford to sell lower than the ones paying for electricity. Result : most of the miners paying get out due to such a low price and we are all screwed as the ponzi collapses.

ITT: People make up electricity rates to convince others of quitting 

how can it be cheaper to buy than produce with free electric.

$1.80? Holy smokes! You must have super, super, super cheap power or something. My two mining rigs together pull about ~850w and at $0.091/khw + current difficulty, I'm only at $20/mo profit.

If price were to drop to $1.80, I'd be out $25/mo!


But that's the point I don't get. What's the fun? If you could just buy the bitcoins for less than it's costing you to mine them.

I get "free" electricity for my small setup, so I have no real shutdown point.  However, my HDD died on my mining rig and right now I could care less that its not hashing while I order a SSD.  The price of a bitcoin is so low that now it's only for fun.  Paid off my cards a long time ago.

$1.80.  That is the electrical cost for my hardware efficiency, current difficulty, and my electrical rate.  Obviously that number would adjust based on difficulty.

Another way to look at it is my cutoff point is (diff/USD BTC price): 854,626.1111  or roughly 850,000.  If difficulty / price is >= 850,000 I quit.  In the wintertime maybe the cutoff is 1 million even (I can always use the "nearly free" heat).

I really have no shutdown point.

Im probably one of the lucky ones, as Im able to keep all my miners at work.  And my miners really didn't cost me anything either as Im able to put them on the books at my business.  Getting close to 2ghash/s now with the addition of my 4th miner.

I think as long as I can buy stuff with btc I will continue mining...

I stated in another thread that breaking below $4 was my bottom line and I've shut down my miners for the time being (until difficulty drop + price increase).

I'm curious: What's your shutdown point?

This isn't a question of "being brave when others are fearful", it's just math. Depending on your electricity cost, you could spend $5 to mine a bitcoin that would only have cost you $4 to just buy.