Quote from: edonkey on September 25, 2014, 04:55:58 AM

Quote from: seriouscoin on September 25, 2014, 04:39:29 AM

Quote from: Rabinovitch on September 25, 2014, 04:16:11 AM

Quote from: mrpark on September 24, 2014, 09:55:24 PM

SP20, SP35 and S4 are all NOTHING BURGERS .... I don't think they will ROI. Seriously, do the math and save your money.

Most of you have a mistake in your equations. They are based on wrong precondition - you somewhy think that BTC's exchange ratio will be the same as now. Try to imagine it will be 600$ in one month, when the miner will pay for itself in this case?

Trust in BTC, otherwise everithing doesn't make sense...

Dumbass if you want to speculate on BTC price, do it right and BUY BTC.

The point here is that you WONT mine back BTCs that you spent on the S4

+1

Personal attacks aside, this is the truth:

If the hardware costs more in BTC than you can mine in a reasonable time, don't buy it.

If you think the BTC is going to go up, then buy BTC.

Mixing currency speculation into your ROI calculations is just wishful thinking...

It's not wishful thinking, unless your power company charges you a constant rate in BTC for a kWh regardless of the exchange rate. At $400/BTC, once the difficulty updates in a few hours someone running an S1 at the default 2J/GH with 13c/kWh power will pull in ~$1.24 a day in BTC, and pay ~$1.25 in power costs.* At $800/BTC, you'd still be making $0.62 a day.

Mining calculations are much more complex now than they used to be when you could effectively ignore the cost of power, especially when you're BTC rich/fiat poor and considering buying hardware with Bitcoin. In that case, you're converting real Bitcoins into hardware in the hope you will produce more Bitcoin, with a very large variable operating cost that depends directly on the price on BTC. If I convert 14.9BTC into 14TH/s with the Prismas and the price stays at 400 , at 10% increase per jump decreasing by 5% per jump, I would only make back about 8.5BTC before I would shut it off. Less BTC than I started with, so bad deal obviously.

If the price immediately jumped to $800 though and stayed there, with the same network conditions I would pay off my 14.9BTC after 28 weeks, even with paying power costs weekly. The massive caveat here is that the network difficulty will behave much differently at $800 than at $400.

*That stat in itself pretty amazing. Without the price going up, there is a lot of relatively recent mining hardware that is going to be shutting off or sold for pennies on the dollar to someone with cheap power. It's only going to take another doubling before people paying 6c/kWh are shutting off S1's, and everyone over 10c/kWh will be effectively mining for nothing with every KnC Jupiter, Cointerra, A1, S2, or HF board made.