Topic: [XPM] [ANN] Primecoin High Performance | HP14 released! - page 9. (Read 397587 times)

About 2x

http://primecoin.org/static/primecoin-paper.pdf

Who can explain as complexity grows, in how many complexity 10.5 is more than complexity 10?

If you don't have any computers with half decent CPUs, then you are out of luck. If you have a bunch of computers around with at least core2duo era CPU then you may be able to make a small profit or attain break even against electricity costs. With my systems at home, in Australia with $0.30/kWh and a bunch of core2/i5/i7 CPUs I was able to only just reach break even against my entire electricity bill (including hot water etc). ie. mining on average $7 to $8 per day and paying that much per day in electricity. However, this was BEFORE diff=10, so it's probably a lot different now.

If you have no electricity costs then you might be able to scrape together a few $/day. Then it purely becomes "how much hardware do you have" and "how cheaply can you attain new hardware".

You probably cannot sustain profitable VPS mining if you had to ask this question. Only consider VPS mining if you run the figures in great detail before you purchase anything. A lot of VPS miners ran at a loss even during the earlier days of primecoin mining, I suspect not too many do it these days now we are past diff 10. The market bolstering caused by BTC-e adding XPM to their site, probably helps a lot if anyone still does VPS mining. I suppose some early VPS miners may have held all their mined XPM and now that the XPM market and BTC price have exploded then they may have done quite well for themselves, but this is a gamble I'd say most people are unlikely to make lightly.

If you want to mine with large profit margins (larger than mining BTC or other SHA-256 altcoins with ASIC) then you should look at scrypt coins "shitcoin flavour of the day" which according to my own (personal situation re electricity) calculations can have margins of 3:1 or 4:1 vs electricity costs and reach "ROI" within 60-90 days. To the best of my knowledge no one mining CPU coins (XPM/PTS/Quark-based) or SHA-256 (inc BTC) can claim such high margins. The biggest downside to scrypt coins seems to be that if you aim to make absolutely maximum return then you need to devote a (un?)reasonable amount of time each day to monitoring the best coin to mine / preparing to mine newly released coins etc... This is only becoming more true as new coins (and even old ones) are adjusting to negate the effects of profit-switching pools, which means that you can no longer even take that lazy option.

If you really want to strike gold with primes, try mersenne.org, they give you a few thousand bucks for each new Mersenne prime

So I compiled this on ubuntu 13.10 and I seem to get a segmentation error/can't connect to server as at approaches or reaches difficulty 10 (when downloading the block).  Is anyone else seeing this?  I have another server running the non updated version for multi-wallet.

error: couldn't connect to server
[1]+  Segmentation fault      (core dumped) ./primecoind


This is in the debug.log
ERROR: mempool transaction missing input


EDIT: I was able to start it up for a very shot period of time before it failed again but I noticed this occurs somewhere between 279042 - 279060 blocks.  I figured it was too much of a coincidence if two separate PCs experienced this at the same time.

If anyone can compile and run this on windows i'll rip one of my ears out.

Has anyone compiled the latest git version for windows 64 ?

how much money can we make off primecoin?

I would like to confirm that the above instructions fix an identical compilation issue on Ubuntu 13.04

I am having trouble getting other computers to mine on the same wallet. What needs to be in the primecoin.conf in order for it to work? Also what would be the best miner to use on i7-2700k and i7-3770k cpus?

Thx, that's very helpful! Is there any kind of documentations on tuning it to maximize the ROI?

Searching for Cunninghan chains (Primecoin/Datacoin mining) involves the following steps:
[Double SHA-256 for the block/block header hashing (CPUs are dreadfully slow for this task)
Modular reduction per sieving prime (using the double SHA-256 result from the block header hash)
Modular multiplicative inverse per sieving prime (using the result from the previous step - we need a starting point for the sieving prime)
Bit array masking or call it sieving (using an array of 32-bit integers that should fit in your CPU's L1 data cache: AMD 64KB, Intel 32KB)
Modular exponentiation on the CPU - sliding window (GMP: Karatsuba + Montgomery reduction)

Now remember that we are searching for chains and not for primes, therefore Primes Per Second (PPS) means absolutely nothing by itself. Your goal is to actually reduce the number of PPS while increasing your number of  probable chains per second (CPS). During your sieving/bit masking process, what you are actually doing is eliminating all of the composite numbers/false chains that would never meet the requirements for your current difficulty. Therefore, the theoretical ratio for difficulty 10 is: 10PPS / 1CPS

So where does tuning come in? First find out if you are running on AMD processors (K10), if so, then double the cache settings and recompile. You may also have to lower your sieve extensions because the AMD processors typically have 64KB/64KB for L1 instruction/data caches. If you are running on Intel processors then Mikaelh's code should work well as is. Tuning involves finding the cutoff point where sieving is no longer as effective as performing modular exponentiation to eliminate false chains per unit of time.

Do you know what PPS is the best to get lucky because I could ramp up the cores to get better results? Like if the PPS is more than 1k then I can have all of my instances average above that number instead of having less with higher PPS. Is this the best strategy?

Well nature does it all the time, it can't be that hard :-)
... Actually, if you don't have a sound mathematical model of how the parameters affect mining performance, it's about the only thing you can do: experiment and adjust.
Of course, just keeping the default parameters which should be well-tested already is a lot easier.

Onkel Paul

Said as if the typical person does them daily.

I do not understand with  10 up to 11 in how many times there will be a difference in processor capacities?

Then you should probably experiment with settings if you believe that the default settings might not be optimal.
For example, you might adjust one setting for half of these instances and run the whole lot for some days to see whether it makes a difference.
If the new setting is better than the old one, use it for the other half and either adjust another setting, or adjust the same setting a little more in the same direction.
Sort of running a genetic optimization algorithm manually.

If you don't want to go through the hassle, you should probably just take the default settings. They are default because the authors thought that they yield best results in normal cases.

Onkel Paul

I have more than 100 instances of VPS!

I think I've said it 1000 times now.

If you just discovered primecoin/hp and you have to ask this question, then the answer is "just leave it alone and run the default settings".

Try not quoting a full page and asking a one liner.