You probably want to take this to the "Marketplace" forum for a sale.

https://bitcointalk.org/index.php?board=75.0

While I don't completely get the math, I do have to ask about the word "expect". Does that mean a 50/50 chance in the week? 95% chance, or what? We've obviously seen pools with 2+ PH that have gone 50 hours between blocks (i.e. bad luck). So it would seem that even with 500 TH you could easily go a week without hitting a block.

That's why I ask about your level of "expectation" in a week (i.e. confidence level).

The tables I saw for the SFARDS chip make it look like a step, but not a leap in efficiency. I don't mean this as a knock, just a recognition of the situation.

My bet is that they will try and get a serious premium for it's "LTC feature", and it will make it appear "overpriced" as a Bitcoin miner only.

Thank goodness this is a speculation thread and I don't have to reveal my overall ignorance of the LTC universe and it's machinations. 

It's really hard to see what value people assign to a Bitcoin. It's value is entirely dependent on what someone else is willing to trade for it, be it merchandise, or some other currency. In that regard, it doesn't seem all that different than the value of a US dollar. It's value clearly isn't derived from the paper and printing. While you can burn dollars for heat, that's pretty much it.

I don't see a cost associated with actually holding Bitcoin. The only cost I see it's volatility. But for the most part Gold has some level of volatility as well, doesn't it? When you put that Gold coin into your safe deposit box it was worth X dollars. When you take it out and try to "spend" it, it might be worth more or less than when it went in. The biggest difference is that Gold (and most precious metals) have alternate uses that put some kind of "floor" under the price, Jewelry, plating, dental work, and so forth have a real value outside of it's monetary exchange value.

Bitcoin has none of that. There is no "alternative use" for a Bitcoin, besides it trade or exchange value.

Eventually we'll see how well it pans out. At the present moment, the big driver of all the mining hardware is the 25BTC "reward" contained within. When that falls to 12.5 and then 6.25, there will be less incentive to have Petahash mining farms sucking down megawatts of electricity. I don't see any way "transaction fees" can support the current huge investment in mining hardware.

The problem is that I think this will take decades, unless Bitcoin collapses in value first.

I don't see how this makes sense. The "next gen" miner could be a "Louder than S5, 1500W, 220V only, $950" device delivered in October that won't fit half the people that contribute early.

Sorry to be "Debbie Downer" but throwing money into a Group Buy of a non-existent Antminer device makes NO sense to me.

Supercomputers aren't cheap to run. Just ask any Cray customer about their cooling and electric bill.

In my opinion, the primary reason to go with a reputable cloud miner is that your locale is too expensive, this could be in the form of taxes or duties on the miner purchase, or the cost of electricity is too high (e.g. $.25 for a KHW), or it's just too hot.

I highlighted "reputable" because many cloud mining operations that PROMISE extraordinary returns can easily be a Ponzi scheme. The "early" folks get paid, perhaps even well. It's the "later" joiners that really get screwed when the cloud mining operation just goes POOF with your money having been sent in.

If you want more rapid and stable payout, you might consider a PPS pool, though the pool fee is usually MUCH higher (e.g. 4% possibly more).

Most other industries recognize the difference between "new" and "used". While I completely understand that Bitcoin mining hardware depreciates way faster than almost anything else, lots of other equipment depreciates while it sits unused. That car that arrives on the dealers lot today, that then doesn't sell until November will sell for less than if it sold next week. It's still "new" and will be treated as such, but the dealer will certainly not expect to receive the same as it sells before the new model year cars start to arrive. It has depreciated in value, even though it hasn't been used by any stretch of the imagination.

The Apple iPhone N-1 that arrived at the Walmart store 3 weeks before the iPhone N, will not sell for the same price as when the first iPhone N-1 was introduced. Walmart understand that it's not as valuable and sells it for less before it depreciates even more. It didn't get used, and still depreciated.

The only real difference is that a Bitcoin miner has a much shorter economic life span than an iPhone or a car.

I would also argue that a miner as used by a mining farm, really isn't all the different from a car that was acquired by Hertz, Avis, National, Alamo and so forth. They are both a machine used to make money. The car just depreciates less quickly than the miner. Both are resold at near then of their economic life span, a few months for the miner, maybe 2-3 years for the rental car. Both had ongoing cost while they were being used, and had risks of damage or loss.

I understand that it's not in the sellers best interest to let the machine sit in a box, but running flat out for a month until somebody actually pays for it and it's shipped on it's way, isn't really the same as "new" is it?

I think the "batch model" is just a manufacturing convenience for the vendor.

I won't belabor the point any more, but obscuring the difference between "new" and "used" is largely driven by the manufacturers to their benefit.

This last difficulty adjust could have easily been a negative .07% if the blocks had fallen slight differently. A stable difficulty is great, a stagnant BTC price of $230 may well tend to keep it there a while longer.  Even if you are manufacturer of the ASIC gear, doubling your farm hashrate doesn't really help much, because a couple of weeks later a positive difficulty adjustment just washes away any gain you had in your hashrate. And unless you installed more efficient gear, you doubled your electric bill, however large or small that may be.

It's possible that the mining community at large has figured out that an ASIC "Arms Race" doesn't really help anyone for very long, unless the BTC price also increases.

I have to agree with Amph here. If underclocking reduces the heat output, then the power draw has been reduced. Watts are Watts and it all ends up as heat one way or another.  It's also typical for a reduced clock frequency to end up with a reduced power draw. This is all standard ASIC "physics", nothing magic.

It is also true that in many/most ASIC designs a reduced frequency would operate correctly with a reduced voltage. If the manufacturer hasn't the provided a means to adjust voltage, or their design makes that impractical (e.g. a string design), then you don't get as much power savings by simply reducing the clock frequency.

While this may be considered normal behavior for a Bitcoin mining manufacturer in the last year or so, it's not normal behavior for a whole host of other vendors. Think Automobile dealer for example. Their new cars sitting on the lot depreciate, though much less quickly than mining gear. You could argue that they should rent them until somebody actually buys them, but there are a whole host of constraints on that kind of behavior in the US. Would you buy a "new" car that already had 3000 miles on it? What about a GPU manufacturer 2 years ago?

I would argue that this definition of "normal behavior" has been forced on purchasers over the last 12-18 months. I don't know if BFL was the first one to do it or not, but it's certainly not limited to them.

Think about it for a minute. Two 1300W power supplies are 2600W. That's 2.6 KW. Run it for an hour, and you have used 2.6KWh.

In your ROI calculations, have you taken into account any possible difficulty adjustments that will likely happen over the next 8 months? While the last 60 days have been relatively "quiet" in terms of difficulty changes, that hasn't always been the case. If you aren't familiar with difficulty adjustments, then read up on them. Every 2016 blocks, the Bitcoins "network" adjusts the difficulty to try and maintain a steady pace of about 14 days to produce those 2016 blocks.If you look back at 2014 for example you can easily find an 8 month period where the difficult adjustment in total was 250%. That means that during your 8th month you are only effectively hashing at 40% of what your were hashing during month 1.

The bitcoinwisdom.com website has the list of pash difficulty adjustments for at least a year. Some were pretty brutal in 2014 (i.e. over 25% in one jump).

It's important that you have a complete picture before you plunk down $2500 on your "money printing" hardware. You MIGHT break even in 8 months. Don't be surprised if you don't.

I will also say to anybody that claims they have "free electricity" to check the realities of of their situation. Somebody is always paying for the electricity they use, but they think it's free" because they have paid for a "normal" amount for their apartment, dorm room, or parent's basement. The key work here is normal, or expected usage amount. Beside the expectation of whoever is paying for the electricity, you will  need to look at the capacity of your electrical service. Student dorm room might have a couple of outlets, probably all on the same circuit. When I went to college, there were serious restriction on things like "hot plates", other high power devices. That wasn't just to annoy folks, it was because the place wasn't wired to support more than some lights, a couple of computers, and maybe a TV. I seriously doubt that college dorms are wired that much better today to support a killowatt or two of Bitcoin mining hardware.

Same thing, on a slightly different scale for your apartment or parent's basement.

Think twice about using your employer's space and electricity for mining. While some may be cool with a small amount of mining that doesn't disrupt things, other employer's have zero tolerance Bitcoin mining on their dime as it were.

One small item of note. While I completely agree that 4 underclocked SP20's are the way to go, Phil's "open door" picture might be a shade misleading. At the time that picture was taken, I'll bet the air temp outside was 5C or less. It's not obvious to me exactly how to best cool a miner when the incoming air is 35C. I get the exhaust plan and all that, but you can't get low temps when you start with 35C air.

Good idea on the Starting Voltage that I hadn't considered. I'll give it a try when I next decide to adjust the settings.

Thanks!!!

I expect that the big killer here is the power input to the ASIC has kept changing with every generation. Kind like why there have been at least a half dozen new socket types, each designed with a specific range of voltage and current inputs. The number of power and ground pins must just continue to grow, since there really isn't any significant I/O to speak for a Bitcoin ASIC (i.e. no PCie or memory pins).

While there are many valid comparisons to Gold mining, the fundamental difference is the difficulty adjustment mechanism. With Gold mining, once you hit a good vein, the harder you mined the more Gold you got. Even if there was zero competition amongst miners, the difficulty adjustment prevents even a single miner from rapidly mining Bitcoin beyond a certain pace, regardless of input effort. And then 10-12 days later, the benefit of all your extra input hash has been dissipated

The one most interesting comparison that resonates with me now: Supposedly in the Gold Rush days, the folks that profited the most were the ones selling mining equipment. While I have no way to validate that assertion, it seems really ironic if correct. 

He just forgot to include the fact that the whole thing is then sealed within an Argon filled chamber. As long as you keep the Oxygen away, it works just great! 

So kinda like "hashing arbitrage"?

Seems less risky than just trading Bitcoins with the inevitable fees whenever you convert BTC to/from USD.

I wonder how long term a strategy this is, though the terms "long term" might be a bit silly in the Bitcoin realm. 

It's interesting that on my one SP20, Loop #3 is the one that has a single "hot" chip on it. It is the same loop, that always exceeds it's power limit by a significant margin. The other 3 loops come in just short of their respective limits, but #3 is at 140W with a limit of 100W.

I have wondered if perhaps the one "hot" ASIC just needs some attention to it's heatsink and thermal paste. Since I am power limiting to about 600W total at the wall, everything runs just fine, and hence I don't really have a compelling reason to monkey with the hardware and risk serious damage.

Has anyone tried to tried to "fix" just one hot chip in their SP20?