Difficulty and BTC/day forecast at current difficulty rate increase

bcpokey

hero member

Activity: 602

Merit: 500

Quote from: Sukrim on June 24, 2011, 03:20:04 PM

Quote from: Chucksta on June 24, 2011, 03:08:21 PM

I never understood the argument for that card, considering the increases in difficulty favours the card that gives the most hash power per USD when initially bought.

/fixed

In the short run (and with increasing difficulty), Hashes per USD on the price tag is THE only thing to look at.

In the longer run (and with constant or falling difficulty), Hashes per Watt used is the dominant measurement.

If you could get a device that costs only 50 USD, uses 3000 Watt per hour and does 1000 MH/s, it would be a better investment currently than FPGAs that cost 500 USD, use 20 Watts and do a few hundred MHashes/sec.

I really should plot out some numbers, as noone did it yet publicly... but that could get quite depressing for 6990 owners/buyers! Wink

Indeed. I've grown weary of trying to debunk these silly static statements, so it's nice to see someone pointing out that context plays a huge role in any decision. $/Mhash, Mhash/Watt, Mhash/Card, $/Watt, Price/Difficulty, Rate_of_Network_Growth, all play an important role in how you choose your path to profitability.

But no, let's just calculate 50% static difficulty increases based on nothing.

Sukrim

legendary

Activity: 2618

Merit: 1007

Quote from: Chucksta on June 24, 2011, 03:08:21 PM

I never understood the argument for that card, considering the increases in difficulty favours the card that gives the most hash power per USD when initially bought.

/fixed

In the short run (and with increasing difficulty), Hashes per USD on the price tag is THE only thing to look at.

In the longer run (and with constant or falling difficulty), Hashes per Watt used is the dominant measurement.

If you could get a device that costs only 50 USD, uses 3000 Watt per hour and does 1000 MH/s, it would be a better investment currently than FPGAs that cost 500 USD, use 20 Watts and do a few hundred MHashes/sec.

I really should plot out some numbers, as noone did it yet publicly... but that could get quite depressing for 6990 owners/buyers! Wink

Chucksta

full member

Activity: 168

Merit: 100

Quote from: AngelusWebDesign on June 24, 2011, 02:29:39 PM

Quote

BTC/Day    $/day   $/mon   $/BTC   Difficulty   Mhash
0.729271757   $12.40   $377.09   17   1379223   1000
0.520908398   $8.86   $269.35   17   1930912.2     1000
0.372077427   $6.33   $192.40   17   2703277.08   1000
0.265769591   $4.52   $137.43   17   3784587.912   1000
0.189835422   $3.23   $98.16   17   5298423.077   1000
0.13559673   $2.31   $70.11   17   7417792.308   1000
0.096854807   $1.65   $50.08   17   10384909.23   1000

Wow -- a Gigahash bringing in 0.26 BTC a day...

I sure hope people stop buying 5830's for $160 at that point, considering it takes almost FOUR of them to make a Gigahash.

+1

I never understood the argument for that card, considering the increases in difficulty favours the card that gives the most hash power.

talldude

member

Activity: 224

Merit: 10

If you want to model this in continuous time inside any given round, here are the parameters:

Assumption: smooth, continuous 50% per round growth rate

Number of blocks generated in current round at time t = 6 * exp(g*t) * t --- g is growth per time, t is time. Working with hours, g = 0.00181. g is derived from simultaneously solving the preceding equation where # of blocks = 2016 and exp(g*t) = (1+per round growth)

BTC/Ghash-hour = 41909/difficulty

With these parameters a round lasts 224 hours, or just over 9 days.

You can create a stepwise function (every 224 hours adjust the difficulty) to find your earnings for any length of time.

WiseOldOwl

full member

Activity: 238

Merit: 100

Quote from: Sukrim on June 24, 2011, 02:22:53 PM

Just get the price up then. Roll Eyes

If you offer to sell lower than what's profitable for you, it's your own fault.

+1

AngelusWebDesign

sr. member

Activity: 392

Merit: 250

Quote

BTC/Day    $/day   $/mon   $/BTC   Difficulty   Mhash
0.729271757   $12.40   $377.09   17   1379223   1000
0.520908398   $8.86   $269.35   17   1930912.2     1000
0.372077427   $6.33   $192.40   17   2703277.08   1000
0.265769591   $4.52   $137.43   17   3784587.912   1000
0.189835422   $3.23   $98.16   17   5298423.077   1000
0.13559673   $2.31   $70.11   17   7417792.308   1000
0.096854807   $1.65   $50.08   17   10384909.23   1000

Wow -- a Gigahash bringing in 0.26 BTC a day...

I sure hope people stop buying 5830's for $160 at that point, considering it takes almost FOUR of them to make a Gigahash.

Sukrim

legendary

Activity: 2618

Merit: 1007

Just get the price up then. Roll Eyes

If you offer to sell lower than what's profitable for you, it's your own fault.

Aaand:

If someone can afford selling lower than you can, it's also your problem. Welcome to the free market.

marvinmartian

full member

Activity: 224

Merit: 100

I'm assuming I can use the same formula that was valid for the last difficulty level, namely:

btcday = 50/((difficulty*49710.2696)/hashrate)

Which is illustrated in the figures below, assuming the difficulty increases at 50% every two weeks for the next several
iterations (late Sept being the last line in the table below). In a little more than 3 months 1gHash will make little more than $1 per day.

Doesn't get much better at $30 per BTC where we'd make $2.91 instead of $1.65 per day.

Bummer.

BTC/Day	$/day	$/mon	$/BTC	Difficulty	Mhash
0.729271757	$12.40	$377.09	17	1379223	1000
0.520908398	$8.86	$269.35	17	1930912.2	1000
0.372077427	$6.33	$192.40	17	2703277.08	1000
0.265769591	$4.52	$137.43	17	3784587.912	1000
0.189835422	$3.23	$98.16	17	5298423.077	1000
0.13559673	$2.31	$70.11	17	7417792.308	1000
0.096854807	$1.65	$50.08	17	10384909.23	1000

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