[QUOTE=ewmayer;374819]But it's not yet been answered by any of our latter-day 49ers.[/QUOTE]They obviously only sell units that have been fully "burned-in" at the factory for a year or two. And when the new hotness units are ready to take over from the old POS units they sell the POS units and start burning in the new hotnesses. So these "new" 28nm units have been "tested" for a while, and the not-yet-for-sale 20nm units are currently being factory "tested". If you blow out the dust, put in new fans with a shiny casing then no one would be able to tell how long it has been "burning-in".

All those may be good reasons. Like "why people are selling/buying MT5 trading experts?", if those are so good to make profit, why the sellers don't use them by themselves to make lots of money? Imagine I could make an expert to double my account every year, should I be so moron to sell it? No, I would keep it secret and guard it with my own life. And after making lots of money I will retire on a nice beach... The reality is that the mother of stupid and credulous people is always pregnant, and the "experts market" is still very profitable (I used to do MT5 tools and sell them too, and even if I am very honest in telling to the people what the expert can do and what it can not do, they are still wanting to buy it, and they dream to get rich overnight).

Back to bitcoin, [URL="https://bitcoinwisdom.com/bitcoin/difficulty"]this[/URL] may be the real reason why people sell the hardware. Stay with your mouse on the thumbnail called "9 months". Every piece of miner you put in the net will increase the difficulty. You buy the hardware now and expect to recover your money in a month or two, but other people think the same, and the difficulty is skyrocketing, so you will need one or two years to come to any profit. Anything can happen in this time, and the risk is big. This may happen to the hardware producer too. And then he does what he knows best: produce hardware and sell it. With no risk, and big profit, you don't imagine that the three blades inside that box cost 3000 dollars to be produced. They are most likely to cost 100 dollars (production cost only) or so. Plus a power supply and few fans in a box. As someone said above, not everybody has the same risk affinity. If you are lucky, you can find a block in first month (about $16K at the actual prices) and you will get the money back with 400% return. If not, you still can crunch for years, or join a pool and do few dollars each day. With 1.3TH you can do about $5 per day (deducting electricity at $0.25, and 1.5KW consumption, includes the computer too, to maintain a wallet, etc, or the net hub, etc). So, you may need more than a year to "recover" the ~$3500 spent on hardware.

It is [B]*not*[/B] a recipe to get rich fast. It is a big risk. But people don't understand this.

Hi All,

I agree with LaurV. Bitcoin is risky business and not a sound investment.

Regards,
Matt

I concur. Bitcoin is for those who are willing to take a risk for the sake of blazing a new trail and don't mind losing their shirts in the process, if it comes to that.

As a straight investment, it was probably OK if you got in at the start (but then, who knew about it at the time?).

My main interest in bringing up the topic was to examine the possibility of using one of those Bitcoin miners for GIMPS, but that's been well answered. (Too bad!)

Now, if somehow we could get GHz-days to be accepted as a digital currency, things might turn out differently. :cool: What would we call it -- Gigahertzcoin? Primecoin?? Mersennecoin??? Bitcoin? -- oh wait, that's already taken...

Rodrigo

Coming back to the original discussion in the thread, Altera just published (today! I am subscribed to their news feed) a [URL="http://www.altera.com/literature/wp/wp-01222-understanding-peak-floating-point-performance-claims.pdf"]very interesting paper[/URL] (entry level, general knowledge, anybody can read it, you don't need math or programming knowledge to understand it) about floating point computing in FPGAs, where a GPU is compared against a DSP and a FPGA. For example, you can read there (the "conclusion" on page 9) about their newest toys which can reach 10 [B][U]tera[/U][/B] flops of... MP (?) calculus (let's call it MP, this term I just invented now, "mid-precision", I didn't know what to write, SP or DP, because they use an intermediary size, with maximum 36 bits of mantissa, so it is nor SP, neither DP) performance. This is something like 10 good GPUs together (or say, 3 Titan Black together, or 3 Tesla K20 together), for just a fraction of power. Yet, the price of such toys are prohibitive.

Following the link through the document reveals more, for who is interested. For example the link about building radar systems on the last page shows you some insight into the FFT calculus in a FPGA and GPU, applied to, of course, radar systems.

Even though there is less financial incentive to develop custom hardware for GIMPS, I think it's still a good idea to talk to ASIC designers. A lot of companies support non-profit groups and may be willing to undertake such a project for a lower fee, if not for free.

[url]http://arstechnica.com/security/2014/06/bitcoin-security-guarantee-shattered-by-anonymous-miner-with-51-network-power/[/url]

[url=https://medium.com/@octskyward/the-resolution-of-the-bitcoin-experiment-dabb30201f7#.et2qupbdj]The resolution of the Bitcoin experiment[/url] | Medium

A.k.a. "how perfectly conceived systems fail in the real world".

I actually purchased a decent FPGA board just for the purposes of "playing with" a TF algorithm and comparing it to the GPUs.

Doing custom LL on an ASIC would be a very cool project - however as others have mentioned beyond incredibly expensive....

There may be more broad market value to an ASIC that could do VERY fast FFTs, which we could use....

[QUOTE=airsquirrels;422753]I actually purchased a decent FPGA board just for the purposes of "playing with" a TF algorithm and comparing it to the GPUs[/QUOTE]

What were the results like?

[QUOTE=airsquirrels;422753]I actually purchased a decent FPGA board just for the purposes of "playing with" a TF algorithm and comparing it to the GPUs.

Doing custom LL on an ASIC would be a very cool project - however as others have mentioned beyond incredibly expensive....

There may be more broad market value to an ASIC that could do VERY fast FFTs, which we could use....[/QUOTE]

Also, something which may be interesting...
[url]http://www.pcworld.com/article/3006601/components-processors/intels-first-server-chip-with-performance-boosting-fpga-to-ship-early-next-year.html[/url]

Intel looks like they'll be releasing hybrid Xeon/FPGA chips this year (Q1 apparently).