Bitcoin Forum

How many Gh/s would I need to solo mine and actually generate blocks on a daily basis.

With ~65GH/s you would on average generate 1 block per day.  Remember that is just an average over the long run, daily results will vary a lot, weekly less, monthly even less, etc.  

The math:
Difficulty = 1307728.3606  (roughly 1.3 million shares per block)
hashes per share = 2^32 hashes
Hashes per block = (1307728.3606)(2^32) = 5.61665E+15 hashes
GH per block = (5.61665E+15) / 1000^3 = 5,616,651 GH
Seconds per day = (60)(60)(24) = 86400 s
GH/s to acheive 1 block per day = 5,616,651 GH / 86400 s ~= 65 GH/s

Thank you for the math.

That's a big number!

That's only 260 ATI 5830's, or just ~$30,000 worth of mining rigs  ;D

lets do some more math :)

260 5830 use about 200 watts a piece or 0.2 kWh

0.2 * 260 = 52 kWh this is the watts used by all cards in a hour
52 kWh * 24 = 1248 kWh per day
1248 kWh * 30 = 37440 kWh per month

now lets say your only paying $0.10 per kWh
1248 * 0.1 = around $124.8 per day
37440 * 0.1 = around $3744 a month

Now lets compare to FPGA's
163 X6500 = 65 Gh/s

each one uses about 20 watts
0.02 * 163 = 3.26 kWh used by all cards per hour
3.26 * 24 = 78.24 kWh per day
78.24 * 30 = 2347.2 kWh per month

again lets say your only paying $0.10 per kWh
78.24 * 0.1 = around $7.824 per day
2347.2 * 0.1 = around $234.72 a month

65 Gh/s will be about 30 blocks a month
30 * 50 = 1500 bitcoins a month

current market price is around $6
6 * 1500 = $9000 a month

$9000 - $3744 = $5256 a month profit for 260 radeon 5830's
$9000 - $234.72 = $8765.28 a month profit for 163 FPGA's



 

Fascinating, but what I have yet to hear in any of the chats or forums surrounding BTC mining at these profitable levels, is what does this stress do to hardware? Say you actually have ~260 video cards running full-tilt and cooled adequately. What's the rate of attrition, are you going to be replacing a card every week that fails? That's math that hasn't been taken in to account... 4 dead cards/month maybe and you're still way ahead but I never seem to see this addressed. Maybe it's not an issue?

Software monitors the temperatures and keeps the cards from overheating and dying. My two 5830s have been mining non-stop since May, without any issues whatsoever. As long as they don't go over 75C, they're fine, since it's not like there's anything physical to wear out on them.

Except fans.  Every fan ever built will eventually die. If someone did build a 60 GH/s farm having a few extra cards and buying a dozen or so spare fans would be smart.

Actually there is (besides fans obviously). Its called electro migration.
http://en.wikipedia.org/wiki/Electromigration

In the long run it will ruin any chip, but that long run could be extremely long indeed. Or just a few months, there is no telling.

That said, without overvolting and while keeping temps reasonable, going by forum reports and a wet finger, you are probably looking at a failure rate of something on the order of 5-10% per year. Perhaps more for 5970s, they seem to be more fragile particularly if you dont take proper care of VRM cooling.

If they are properly cooled, electromigration won't kill them, they will last for years and years

I find it easier to just play the currency markets or offer goods/services for Bitcoins personally. Solo mining rarely yields anything unless you have some major hardware and pool mining yields a minute % of a bitcoin in a day while cranking your resource usage to 100% for long periods of time.

FYP

Electromigration is unavoidable and irreversible.  It will in time destroy every chip produced.

You can avoid EM; all you have to do is never power the chip up :)

A BURN.  You got me there. :)

Only if you power the chip up. 

I just got into bitcoins. Recently, before bitcoins, I have been looking at mining energy. What I mean by that is looking at ways to make heat for the home, etc.  Passive solar is nice and eventually free once you recoup costs for the creation of the passive device. But I also came across a design that uses $200 of materials and can generate 90,000 BTU. using grass clippings, kitchen scraps, straw, paper, just about anything it seems.

1 watt = 3.41 BTU
90,000 BTU = 26,400 watts = 26.4 kWh

So if you pay to heat your home already but instead use this device to do the heating and you have access to enough materials you could use those watts toward mining.  There are all kinds of numbers to be played with here of course, but you get the idea.

To generate 90,000 BTU requires lots of material, I think the rate of material exhaustion was ~4 hours. But even doing 22,500 BTU or 16 hours
would mean more free watts that you saved from using to heat your place. There's also some waste heat from the mining rig.

Mow lawns to make bitcoins!  I think manure works well. Municipalities could generate lots of BTUs from human waste.
Maybe we could mine bitcoins by using the toilet. Energy is everywhere!

There is a device like this being developed in a sort of hush hush manner by a group in University of Maryland, and they plan on selling it for about $5,000 per generator (last I heard, about a year or two ago). Not sure if that'll go anywhere though :/

I get a lonely 255MHash/s with my 6850 :/