Bitcoin miner for GIMPS...

[xilman]

Originally Posted by ixfd64

It would certainly be cool if there was an ASIC for trial factoring or Lucas-Lehmer tests. Unfortunately, I don't think we'll see any custom GIMPS hardware anytime soon because there is no monetary incentive for developing it. People don't earn money crunching for GIMPS as they would mining Bitcoins.

I'm trying to teach myself Verilog and FPGA design. Perhaps a TF implmentation may be forthcoming. Don't bet on it happening any time soon, unless anyone else wants to work with me.

Even so, it's unlikely (IMAO) that a sufficiently fast implementation will happen any time soon.

[ewmayer]

Originally Posted by ixfd64

People don't earn money crunching for GIMPS as they would mining Bitcoins.

Good thing, too, because the only thing worse than spending lots of time writing custom code for a specialized problem and not getting paid for it, is doing so for a tech-geek fad which serves no remotely useful purpose except perhaps to enrich one's local electric utility.

(And before the bitCon fanbois pipe up with their delusions of "decentralized money beyond government reach, dude", see here for recent analysis of the fraud/scam aspects of BTC, and here for why governments would love nothing better than an all-digital currency paradigm - under their control, of course, which is the inevitable price for any such currency to become truly wide-scale adopted.)

[chalsall]

Originally Posted by ewmayer

Good thing, too, because the only thing worse than spending lots of time writing custom code for a specialized problem and not getting paid for it, is doing so for a tech-geek fad which serves no remotely useful purpose except perhaps to enrich one's local electric utility.

Oh, I'm not sure you are correct...

Being able to experiment with distributed systems, software, hardware and social media might have some up-side...

I believe a book was recently written about exactly this....

[alpertron]

GPUs are optimized for single precision arithmetic. So it is possible to have a big boost if using ASIC for doing large multiplies.

When using hardware, there is no need to use FFT. You can use the hardware to perform multiplication of extremely big numbers by using, say, 1024-bit hardware multipliers and then multiply and add 1024-bit chunks.

For numbers about M102400000, the multiplication could be done in k*100000 clock cycles, where k is a very small number. Of course you would need 100000 of these multipliers operating in parallel.

To fix the idea suppose k=5, frequency = 1GHz (which it is not too fast).

Then the complete LL would require 5*100000*102400000/10⁹ = 51200 seconds.

This would need about 1 billion gates to work. I think it is too much for current technology, especially if we want to use this method up to M999999999, but the speedup would be awesome.

[retina]

Originally Posted by alpertron

When using hardware, there is no need to use FFT. You can use the hardware to perform multiplication of extremely big numbers by using, say, 1024-bit hardware multipliers and then multiply and add 1024-bit chunks.

I think you would be better off using NTT. Even using Karatsuba here would be rather silly for numbers of that size.

[jasonp]

Building an ASIC means you are paying someone to build a custom chip for you; in fact you are paying someone to retool an entire production line in an overseas factory to build a custom chip for you. Depending on how badass your chip is, the one-time cost (NRE, or non-recurring-engineering) for doing that can be millions of dollars. The software that even lets you design a large ASIC can itself cost millions of dollars.

By comparison, building your logic into an FPGA costs a few hundred dollars for a development board, software that is usually downloaded for free, and a ton of your time. The downside is that FPGAs are much more constrained compared to ASICs, both in the amount of logic they have and the speed at which that logic runs. A nice latter-day Xilinx FPGA has hundreds of 17-bit multipliers and several megabytes of on-chip memory, running at ~600MHz, but those chips cost $3k-10k each. That kind of money can buy you a room full of PCs with GPUs.

[LaurV]

Originally Posted by ewmayer

And before the bitCon fanbois pipe up with their delusions of "decentralized money beyond government reach, dude",

I don't wanna stole the thread, what you show there is what EVERY Forex broker does. Should that mean the actual currencies we use (EUR, USD, JPY, etc) are all scams? I remember the FXCM scandal in 2003 or so (yes, I was trading for so long, didn't get rich, because I didn't risk a lot, but didn't get swapped away too, at the time it was called FX LTC or something like that, they were my first broker, to which I lost $3800 in few months, in few different accounts, it was how I started). That scandal sounded the same as the one you linked (about mtgox) except the numbers.

Now, after the thing gone (I didn't have any money with mtgox, sorry for the people who lost their money there - that's life!, I still have my bitcoins, didn't sell them) I see this as a positive thing for the coin itself. Guys trying to profit from it were swapped away. So what?

In fact, this confirm what I said before. They were trying to grab the control of the bitcoin market for themselves, they got their asses shaved. The rest is collateral damage. Bitcoin is still well, thanks for asking...

[ewmayer]

Indeed, in the sense that their "value" derives from a set of assumptions and promises, "faith" if you will, all fiat currencies are scams. But in this arena there is a crucial difference between government-mandated scams and 3rd-party scams. I know it's not fair, just as death and taxes aren't fair.

Re. the sellers of custom digit-twiddlingmining hardware, a question: If it is so easy to make profits from mining on said equipment, why would said companies ever want to part with it? Why not keep it and make huge profits by their own large-scale mining? Their profit potential would even be quite a bit higher than that of Joe Schmoe retail-customer Miner, due to the fact that they get the gear at cost, and can take advantage of similar economies of scale in mining as exist in the manufacture of said equipment.

[retina]

Originally Posted by ewmayer

Re. the sellers of custom digit-twiddlingmining hardware, a question: If it is so easy to make profits from mining on said equipment, why would said companies ever want to part with it? Why not keep it and make huge profits by their own large-scale mining? Their profit potential would even be quite a bit higher than that of Joe Schmoe retail-customer Miner, due to the fact that they get the gear at cost, and can take advantage of similar economies of scale in mining as exist in the manufacture of said equipment.

It has been asked before.

http://www.mersenneforum.org/showthr...499#post368499

[ewmayer]

Originally Posted by retina

It has been asked before.

http://www.mersenneforum.org/showthr...499#post368499

But it's not yet been answered by any of our latter-day 49ers.

[Mini-Geek]

Originally Posted by ewmayer

Re. the sellers of custom digit-twiddlingmining hardware, a question: If it is so easy to make profits from mining on said equipment, why would said companies ever want to part with it? Why not keep it and make huge profits by their own large-scale mining? Their profit potential would even be quite a bit higher than that of Joe Schmoe retail-customer Miner, due to the fact that they get the gear at cost, and can take advantage of similar economies of scale in mining as exist in the manufacture of said equipment.

Because they can shift the risk to their customers. They might both come out ahead. They might not. "We can create hardware for $X and sell it for $Y" is a much better proposition than "We can create hardware for $X and hopefully in the future sell the bitcoins it produces for $Z". (X < Y < Z) And, for the appropriately risk-tolerant customers (a.k.a. gamblers), "I can buy hardware for $Y and hopefully sell the bitcoins for $Z" is acceptable.

Plus, if the company was able to build enough hardware to make it over 50% of the mining power, the community would be suspicious of possible 51% attacks...you don't want to shoot yourself in the foot by tanking bitcoin's price after spending millions on custom hardware. (letting the hardware be distributed removes/lowers this risk)