Profit and LossLooking at my Gridseeds and wondering if I should mod the hardware, and if so by how much, it seemed to me that the alarming increase in power usage as clock speed increases might have undesirable effects on the profitability. So I decided to get out my calculator. The results below are based on some tests performed by myself on the latest version of the Gridseed 5 chip module (the one with surface mount LED's). I modified one by changing R52 to 39k and another by changing R52 to 47K. The modules all had the 5V fan mod and were clocked at 850MHz, 1000MHz and 1200MHz, these values were chosen as the maximum which gave zero (or close to it) errors. The power cost is calculated from what I pay at about $0.20/KWHour and the modules using 4W, 15W and 25W. All figures relate to one Gridseed module running for one day and based on a bitcoin value of $460. Earnings figures are based upon a return of 0.004386 BTC/MHash/day.
| R52 | Power Cost | Earns Today | Profit Today | Earns Month 2 | Profit Month 2 | Earns Month 3 | Profit Month 3 |
| 33k(standard) | $0.019 | $0.72 | $0.701 | $0.36 | $0.341 | $0.18 | $0.161 |
| 39k | $0.072 | $0.857 | $0.785 | $0.4285 | $0.3565 | $0.21425 | $0.14225 |
| 47k | $0.12 | $1.029 | $0.909 | $0.5145 | $0.3945 | $0.25725 | $0.13725 |
So assuming that the income from mining halves each month (seems likely it will) we can see that in just 2 or 3 months time it will be best to have unmodified Gridseeds.
I must emphasise that these figures are far from definitive and should only be viewed as a rough estimate. Your modules might give different results and your power cost is probably different from mine.
Overall I think my best bet is to leave mine standard with no fans at all rather than go to all the trouble of modding them only to have to put them back in a month or two.
Almost precisely the reason why I reverted my mods back to default without fans (except for a single 120mm fan running at 5v cooling 14 GS).
My simple reasoning was this. Why would I make the mod to double the hashrate when it quadruples the power consumption? Which produces more heat requiring the need for more cooling?
I admit, the mod is a great endeavor if the cost of power is factored out of the equation, ie gamers with their graphics cards. Those gamers push for more gpu cycles irregardless of power costs.
Did some thinking about this, and think there is some room for interpretation of the results.
Some points of interest,
Im paying only $0.10/KWH where I live (Arizona). I know rates vary all over the US as well as internationally, so the degree to which the wattage increase will affect you strongly depend on those local rates.
Im a bit concerned about the difficulty factors as well. For sure, no-one knows what will happen with difficulty, which is why this is open to large-scale debate. I won't presume to fault your numbers, but I want to offer an alternative viewpoint (which may be wrong, I admit).
My feeling is that the GSD devices don't offer a significant change in the overall hashrate compared to GPU's. They are in the same ballpark for hash-rate, as well as price/KHs. At-least roughly speaking. I mean that from the perspective of GSD at around 0.4 $/KHs and GPUs in the 1-2 $/KHs.
So, from my point of view, I don't expect to see any radical change in the global hashrate in the NEAR future due to the GSD marketplace.
That said, when some of the "second-generation" ASIC's hit the market later this summer (Fibonacci, KNC, Alpha, etc), those do offer the potential for a significant increase in the global hash-rate. It's when those ASICs hit the market that I would expect to see the difficulty start to spike.
I also know it's imossible to predict the future with any accuracy, so I would like to offer this alternative viewpoint on the difficult factors...
From Jan-now, LTC went from a difficulty around 3K to around 6K. If you divide that into the number of difficulty adjustments which occured, you find the average difficulty increase for 2014 (so-far) has been about 2.3% per increment. Im hoping this trend continues untill around July-Aug when the next-gen ASICs hit the market at which point it will spike much quicker (in my opinion).
That said, I think we have a window of time untill July to try and recoup as much as possible from the GSDs. After that, the chances of any ROI will dwindle rapidly.
Anyhow, just my opinion